Resuggestion, thanks to Xerogyf for the info!

Sale 1:

https://backpack.tf/profiles/76561199015520369#!/compare/1589673600/1590364800

https://backpack.tf/profiles/76561198119635547#!/compare/1589155200/1591401600

Bulk

sale 2:

https://backpack.tf/profiles/76561198173925222#!/compare/1591315200/1596153600

https://backpack.tf/profiles/76561199030867152#!/compare/1596153600/1596153600

https://backpack.tf/profiles/76561198242067104#!/compare/1596067200/1596153600

Bulk / untrace

sale 3:

https://backpack.tf/profiles/76561198116559834#!/compare/1590883200/1592006400

https://backpack.tf/profiles/76561198195345970#!/compare/1590796800/1590883200

Can trace ~2 keys in sweets

Sale 4:

https://backpack.tf/profiles/76561198358296372#!/compare/1590105600/1590192000

https://backpack.tf/profiles/76561198097816819#!/compare/1590105600/1590192000

Likely for 4 keys (bot.tf)

sale 5:

https://backpack.tf/profiles/76561198335791307#!/compare/1594771200/1594857600

https://backpack.tf/profiles/76561199018021198#!/compare/1594771200/1594857600

Sold for 4.21 keys (bot.tf, and keys physically show up. no history / ID match, however....)

Sale 6:

https://backpack.tf/profiles/76561197989494507#!/compare/1591574400/1596153600

https://backpack.tf/profiles/76561198092970200#!/compare/1593388800/1593475200

Untrace

sale 7:

https://backpack.tf/profiles/76561198334598690#!/compare/1589155200/1589241600

https://backpack.tf/profiles/76561198146343034#!/compare/1589068800/1589328000

Keys

sale 8:

https://backpack.tf/profiles/76561198146343034#!/compare/1591401600/1591574400

https://backpack.tf/profiles/76561198358296372#!/compare/1591315200/1591401600

QS

sale 9:

https://backpack.tf/profiles/76561198358296372#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198082401774#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198448501306#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198082401774#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198358296372#!/compare/1592524800/1592611200

bought, transferred, QS.

sale 10:

https://backpack.tf/profiles/76561198358296372#!/compare/1592870400/1592956800

https://backpack.tf/profiles/76561198296326711#!/compare/1592956800/1593043200

Sold for ~3.65 keys

sale 11:

https://backpack.tf/profiles/76561197992711280#!/compare/1590278400/1590537600

https://backpack.tf/profiles/76561198228125224#!/compare/1589328000/1591747200

Untrace

sale 12:

https://backpack.tf/item/4583987169

https://backpack.tf/profiles/76561198366622633#!/compare/1592092800/1593129600

not unusual before this sale

sale 13:

https://backpack.tf/profiles/76561198085880346#!/compare/1589673600/1589760000

https://backpack.tf/profiles/76561198277373335#!/compare/1589587200/1589673600

tradeback

sale 14:

https://backpack.tf/profiles/76561198277373335#!/compare/1589673600/1589760000

https://backpack.tf/profiles/76561198085880346#!/compare/1589673600/1589760000

tradeback

sale 15:

https://backpack.tf/profiles/76561198183896105#!/compare/1590278400/1590624000

https://backpack.tf/profiles/76561198280693486#!/compare/1590451200/1590537600

QS for ~2.75 keys

sale 16:

https://backpack.tf/profiles/76561198280693486#!/compare/1590710400/1590796800

https://backpack.tf/profiles/76561198109749673#!/compare/1590192000/1590796800

Sold for ~3.51 keys

sale 17:

https://backpack.tf/profiles/76561198340634356#!/compare/1589155200/1589241600

https://backpack.tf/profiles/76561198098646232#!/compare/1588982400/1589241600

Sold for ~3.71 keys

sale 18:

https://backpack.tf/profiles/76561198103357973#!/compare/1589932800/1592870400

https://backpack.tf/profiles/76561199018021198#!/compare/1589846400/1589932800

Sold for 3 keys (possibly 4, might have sold 1 for refined, but cannot trace)

Sale 19:

https://backpack.tf/profiles/76561199018021198#!/compare/1593820800/1593907200

https://backpack.tf/profiles/76561198174778935#!/compare/1594080000/1594080000

Untrace

sale 20:

https://backpack.tf/profiles/76561198015404086#!/compare/1590019200/1591833600

https://backpack.tf/profiles/76561198104220733#!/compare/1591747200/1591833600

untrace

sale 21:

https://backpack.tf/profiles/76561198838468618#!/compare/1590192000/1590278400

https://backpack.tf/profiles/76561198446211212#!/compare/1590105600/1590278400

https://backpack.tf/profiles/76561198448504337#!/compare/1590624000/1590710400

https://backpack.tf/profiles/76561198850274253#!/compare/1590710400/1590796800

Not unusual

sale 22:

https://backpack.tf/profiles/76561198850274253#!/compare/1591401600/1591488000

https://backpack.tf/profiles/76561198049556321#!/compare/1591488000/1591920000

Sold with ~1.38 keys in sweets for ~5.3 keys in sweets

Total is 3.92 keys

Sale 23:

https://marketplace.tf/items/tf2/1109;5;u3005

$9 / $1.88 = 4.79 keys

$9 / $1.90 = 4.74 keys <--- https://backpack.tf/item/8242739353

$8.99 / $1.89 = 4.76 keys

$14 / $1.96 = 7.14 keys

$6.2 / $1.98 = 3.13 keys

$14.85 / $1.98 = 7.50 keys <--- https://backpack.tf/item/2768767037

$6.55 / $2.02 = 3.24 keys

$8 / $1.99 = 4.02 keys

$9.6 / $1.98 = 4.85 keys

$6.71 / $1.90 = 3.53 keys

Bot.tf:

https://bot.tf/stats/item?def=1109&q=5&ef=Fountain%20of%20Delight&craft=1&aus=0&ks=0&source=browser_script

3 @ 3 keys,

1 @ 3.7 keys,

2 @ 4 keys

3 @ 3.65 keys,

1 @ 4.2 keys

Total sales @:

2.75

3 (x4)

3.15

3.25

3.55

3.65 (x4)

3.7 (x2)

3.9

4 (x5)

4.2 (x2)

4.75 (x2)

4.8

4.85

7.15

7.5

buyers up to ~3.1 keys, one high buyer for 3.16 keys,

months unsold at 8,

month unsold for 7,

poorly bumped aging seller for ~4.35 keys,

aging seller for ~4.25 keys,

sellers on MPTF for ~3.5, 3.55, 3.6 keys for months,

let's call 3 low,

4.75 high,

Xergoyf’s Part:

I think you double counted some of the bot.tf sales (from normal sales & bot.tf stats) in your total sales. This means there is only 1 sale @ 4.2 for the high-end. There is no id match on that sale because the buyer re-sold to a bot soon after, which means it should probably be excluded. I would also prob exclude 3.15 given the buyer at that price, also a mp buyer quite close to that price as well, and given it being in between two much higher mp sales, was probably to a buy order.

While a small fix, 3.25 - 4 should be better.