This is my first suggestion, if I did anything wrong feel free to let me know. Credits to Hašlerka for confirming my sales with screenshots.

Note: Some item histories do not show the item as existing, but going through inventory comparisons will lead you to that specific item history. They all can be confirmed through the inventory time comparisons if you’d like to do that.

Sale #1 - FEB 08 2016

Stormy Storm Prince Tavish's Crown + ~5 keys in items sold for Orbiting Fire Defiant Spartan (16 keys, mini below) + ~3 keys in items

[url]https://backpack.tf/profiles/76561198189500328/#!/compare/1454745600/1454918400[/url]

[url]https://backpack.tf/profiles/76561198112757232/#!/compare/1454745600/1454918400[/url]

Screenshot of the trade: [url]http://imgur.com/ACVGPrp[/url]

= 14 keys

Here is the full trade:

Stormy Storm Prince Tavish's Crown: [url]https://backpack.tf/item/488895001[/url]

Buck Turner All-Stars #26040 (An Extraordinary Abundance of Tinge) (12 ref): [url]https://backpack.tf/item/3988403008[/url]

Strange Killstreak Scotsman’s Skullcutter (~7 ref): [url]https://backpack.tf/item/1103035162[/url]

Strange Specialized Killstreak Grenade Launcher (~2 keys): [url]https://backpack.tf/item/3263478534[/url]

The Bearded Bombardier (7 ref): [url]https://backpack.tf/item/3938024475[/url]

The Ward (3.66 ref): [url]https://backpack.tf/item/3433023542[/url]

Physician's Procedure Mask (3.33 ref): [url]https://backpack.tf/item/3850529022[/url]

Strange Specialized Killstreak Masked Mender Festive Medi Gun (Field-Tested) (~6 ref): [url]https://backpack.tf/item/3955896801[/url]

Strange Specialized Killstreak Carbonado Botkiller Stickybomb Launcher Mk.I (~1 key): [url]https://backpack.tf/item/1955250658[/url]

(Stormy Storm Prince Tavish's Crown + ~5 keys) for (Orbiting Fire Defiant Spartan + ~3 keys)

Orbiting Fire Defiant Spartan (Voices from Below) (~16 keys, mini below): [url]https://backpack.tf/item/785508236[/url]

Strange Cow Mangler 5000 (1 ref): [url]https://backpack.tf/item/3599835274[/url]

Strange Third Degree (1 ref): [url]https://backpack.tf/item/4522059702[/url]

Professional Killstreak Airstrike (~1 keys): [url]https://backpack.tf/item/4448668135[/url]

Ein (1.55 ref) - [url]https://backpack.tf/item/4563080311[/url]

Wanga Prick #379300 (<1 ref) - [url]https://backpack.tf/item/4548626213[/url]

Cold Snap Coat (~1.4 keys) - [url]https://backpack.tf/item/3454383372[/url]

Strange Market Gardener (4.5 ref) - [url]https://backpack.tf/item/923451298[/url]

Dressed to Kill Shotgun (Field-Tested) (<1 ref)- [url]https://backpack.tf/item/4441562527[/url]

Mini for Orbiting Fire Defiant Spartan - JAN 27 2016

[url]https://backpack.tf/profiles/76561198112757232/#!/compare/1453881600/1453968000[/url]

Orbiting Fire Defiant Spartan - [url]https://backpack.tf/item/785508236[/url]

Bubbling Cosa Nostra Cap (16 keys, mini below)- [url]https://backpack.tf/item/907713594[/url]

Listings for Bubbling Cosa Nostra Cap are currently 16 keys, assuming price is still accurate: [url]http://imgur.com/4Yqfxa5[/url]

Also below, was recently sold for around 15-16 keys in items

Mini for Bubbling Cosa Nostra Cap - JAN 27 2016

Sold for ~15.5 keys in items

[url]https://backpack.tf/profiles/76561198112757232/#!/compare/1453795200/1453881600[/url]

[url]https://backpack.tf/profiles/76561198063604219/#!/compare/1453708800/1453881600[/url]

Screenshot of the trade: [url]http://imgur.com/BQrGQga[/url]

= 15-16 keys

Here is the full trade:

Bubbling Cosa Nostra Cap: [url]https://backpack.tf/item/907713594[/url]

(Bubbling Cosa Nostra Cap) for (~15.5 keys)

Vintage Glengarry Bonnet (4.77 ref): [url]https://backpack.tf/item/58544750[/url]

Non-Craftable Prussian Pickelhaube (Australium Gold) (1.22 ref): [url]https://backpack.tf/item/418112584[/url]

Strange Professional Killstreak Liberty Launcher (Gib Kills) (~2.5 keys): [url]https://backpack.tf/item/795005632[/url]

Strange Killstreak Degreaser (~2 keys): [url]https://backpack.tf/item/1050330580[/url]

Strange Scattergun (Domination Kills, Point Blank Kills) (~5 ref): [url]https://backpack.tf/item/1173334753[/url]

Genuine Tartantaloons (4.77 ref): [url]https://backpack.tf/item/2009056124[/url]

Strange Revolver (Spies Killed) (~1.44 ref): [url]https://backpack.tf/item/2382447663[/url]

The Shred Alert (13.66 ref): [url]https://backpack.tf/item/2482688399[/url]

Non-Craftable Professional Killstreak Spy-cicle (~2 keys): [url]https://backpack.tf/item/2686496005[/url]

Professional Killstreak Tribalman's Shiv (~2 keys): [url]https://backpack.tf/item/3154387272[/url]

Killstreak Eureka Effect (~10 ref): [url]https://backpack.tf/item/3619627817[/url]

Texas Ten Gallon (2.66 ref): [url]https://backpack.tf/item/3681432821[/url]

The Shogun's Shoulder Guard #16020 (6.66 ref): [url]https://backpack.tf/item/3724388678[/url]

Rancho Relaxo (9.55 ref): [url]https://backpack.tf/item/3892190646[/url]

Citizen Pain Minigun (Factory New) (3 ref): [url]https://backpack.tf/item/3918933197[/url]

Commissar's Coat (6 ref): [url]https://backpack.tf/item/4217457616[/url]

Specialized Killstreak Original (~1 key): [url]https://backpack.tf/item/4041186554[/url]

The Flared Frontiersman (Muskelmannbraun) (1.44 ref): [url]https://backpack.tf/item/4253959338[/url]

The Team Captain #51338 (6.33 ref): [url]https://backpack.tf/item/4257692967[/url]

Strange Scorch Shot (2 ref): [url]https://backpack.tf/item/4433003594[/url]

The Bruiser’s Bandanna #12875 (The Bitter Taste of Lime and Defeat) (1 key): [url]https://backpack.tf/item/4454113058[/url]

El Patron (Muskelmannbraun) (2.33 ref): [url]https://backpack.tf/item/4376640203[/url]

Only including the calculations due to the large amount of ref numbers:

4.77 + 1.22 + 5 + 4.77 + 1.44 + 13.66 + 10 + 2 + 6.66 + 9.55 + 3 + 6 + 1.44 + 6.33 + 2 + 2.33 = 80.17 ref

2.5 + 2 + 2 + 2 + 1 + 1 = 10.5 keys

This adds up to above 15 keys, and may have been valued as more due to lime paint, gib kills, domination kills, or all. Pricing at 16.

Sale #2 - FEB 24 2016

Sold for Blizzardy Storm Glengarry Bonnet (14 keys)

[url]http://backpack.tf/profiles/76561198111247068/#!/compare/1453622400/1456300800[/url]

[url]http://backpack.tf/profiles/76561198138632646/#!/compare/1456214400/1456300800[/url]

Screenshot of the trade: [url]http://imgur.com/kyGGjAr[/url]

= 14 keys

No full trade details needed, is 1:1

Sale #3 - MAR 21 2016

Stormy Storm Prince Tavish's Crown + ~3 keys in items sold for 5 keys pure + ~12.5 keys in items

[url]https://backpack.tf/profiles/76561198137148352/#!/compare/1458284400/1458543600[/url]

[url]https://backpack.tf/profiles/76561198112757232/#!/compare/1458457200/1458543600[/url]

= 14.5 keys

Here is the full trade:

Stormy Storm Prince Tavish’s Crown: [url]https://backpack.tf/item/488895001[/url]

Strange Specialized Killstreak Hitman's Heatmaker (Heavies Killed, Snipers Killed, Headshot Kills) (~1 key): [url]https://backpack.tf/item/1914176583[/url]

Strange Killstreak Scotsman’s Skullcutter (~7 ref): [url]https://backpack.tf/item/1103035162[/url]

The Five Month Shadow (4 ref): [url]https://backpack.tf/item/4614673998[/url]

Buck Turner All-Stars #26040 (An Extraordinary Abundance of Tinge) (12 ref): [url]https://backpack.tf/item/3988403008[/url]

The Bearded Bombardier (7 ref): [url]https://backpack.tf/item/3938024475[/url]

Sir Hoots A Lot (2 ref): [url]https://backpack.tf/item/4539378400[/url]

The Five-Month Shadow (4 ref): [url]https://backpack.tf/item/4614673998[/url]

(Stormy Storm Prince Tavish's Crown + ~3 keys) for (5 keys pure + ~12.5 keys)

Strange Specialized Killstreak Degreaser (~2 keys): [url]https://backpack.tf/item/538340334[/url]

Villain’s Veil #30384 (6 ref): [url]https://backpack.tf/item/1958798480[/url]

The Swagman’s Swatter #47113 (1.66 ref): [url]https://backpack.tf/item/607896002[/url]

The Chronomancer #7047 - (5.66 ref): [url]https://backpack.tf/item/2691856186[/url]

The Breakneck Baggies (10 ref): [url]https://backpack.tf/item/3127933289[/url]

Mann Co. Supply Crate Key #1 :[url]https://backpack.tf/item/3788785276[/url]

Mann Co. Supply Crate Key #2 :[url]https://backpack.tf/item/3900602598[/url]

Mann Co. Supply Crate Key #3 :[url]https://backpack.tf/item/3949273355[/url]

Mann Co. Supply Crate Key #4 :[url]https://backpack.tf/item/4631510296[/url]

Mann Co. Supply Crate Key #5 :[url]https://backpack.tf/item/4632736441[/url]

Non-Craftable Specialized Killstreak Flare Gun (~1 key): [url]https://backpack.tf/item/4185830690[/url]

The Hood of Sorrows (~2.2 keys): [url]https://backpack.tf/item/4388081690[/url]

Treasure Hat - (6 keys): [url]https://backpack.tf/item/198747457[/url]

Sale #4 - MAR 25 2016

Sold for 13 keys pure + ~3 keys in items

[url]http://backpack.tf/profiles/76561198138632646/#!/compare/1458777600/1458864000[/url]

[url]http://backpack.tf/profiles/76561198262775481/#!/compare/1458716400/1458864000[/url]

Screenshot of the trade: [url]http://imgur.com/MD7NKwR[/url]

= 16 keys

Here is the full trade:

Stormy Storm Prince Tavish’s Crown: [url]http://backpack.tf/item/1128969003[/url]

(Stormy Storm Prince Tavish’s Crown) for (13 keys pure + ~3 keys)

Mann Co. Supply Crate Key #1: [url]http://backpack.tf/item/4266261974[/url]

Mann Co. Supply Crate Key #2: [url]http://backpack.tf/item/4392450130[/url]

Mann Co. Supply Crate Key #3: [url]http://backpack.tf/item/3110635579[/url]

Mann Co. Supply Crate Key #4: [url]http://backpack.tf/item/4630013897[/url]

Mann Co. Supply Crate Key #5: [url]http://backpack.tf/item/4630013898[/url]

Mann Co. Supply Crate Key #6: [url]http://backpack.tf/item/4630013900[/url]

Mann Co. Supply Crate Key #7: [url]http://backpack.tf/item/4630013908[/url]

Mann Co. Supply Crate Key #8: [url]http://backpack.tf/item/4630013905[/url]

Mann Co. Supply Crate Key #9: [url]http://backpack.tf/item/4630013909[/url]

Mann Co. Supply Crate Key #10: [url]http://backpack.tf/item/4630013910[/url]

Mann Co. Supply Crate Key #11: [url]http://backpack.tf/item/4630013906[/url]

Mann Co. Supply Crate Key #12: [url]http://backpack.tf/item/4630013911[/url]

Mann Co. Supply Crate Key #13: [url]http://backpack.tf/item/4630013903[/url]

Genuine Anger (12 ref): [url]http://backpack.tf/item/504723829[/url]

The Point and Shoot (16 ref): [url]http://backpack.tf/item/3743830308[/url]

Taunt: The Schadenfreude (15.66 ref): [url]http://backpack.tf/item/3506686484[/url]

The Level Three Chin (5 ref): [url]http://backpack.tf/item/4438558424[/url]

The Festive Sandvich (5.66 ref): [url]http://backpack.tf/item/1361029357[/url]

Current Sellers:

[url]http://www.tf2outpost.com/trade/27983499[/url] - unsold for a few days at 23 keys

Note: I’m not sure whether to price the Strange Specialized Killstreak Hitman's Heatmaker at 1 key or 3 keys, since all three of the strange parts are high demand on a sniper rifle, but pricing it at 1 since parts generally don’t count. I didn’t price any paints. Also, if any of my estimated price for an item does not match with the backpack.tf price, its because I checked and they don’t sell for their bp.tf price. Ex: proks airstrike is 1 key, since the kits normally go for around 1 key, and since the air strike is unique, so it is 1 key, not 2 (steam market), which is listed. Please let me know if I’m not supposed to do this, I’m not familiar with suggestion rules.

14-16 keys seems like a good range, but any advice or constructive criticism would be appreciated.