Sale #1:

http://www.tf2outpost.com/trade/26069682

Sold for Burning Hive Minder (160) + Anti-Freeze Caribbean Conqueror (106) + ~16 keys in items

Buyer:

http://backpack.tf/profiles/76561198055358018?time=1433487600 (June 5th)

http://backpack.tf/profiles/76561198055358018?time=1433574000 (June 6th)

Seller:

http://backpack.tf/profiles/76561198056793885?time=1433487600 (June 5th)

http://backpack.tf/profiles/76561198056793885?time=1433574000 (June 6th)

Items received: http://i.imgur.com/IkUD96e.png (Botkiller Sniper Rifle is Pro KS, ~8 keys?)

The Samur-Eye was traded for the items in the 2nd sale on the same day.

(160 + 106 + 16) * 0.9 = 253.8; rounded to 250 keys

Sale #2:

http://backpack.tf/item/1222635761 (Between Desert and Chuffs)

Sold for duped Sparkle Luger (200 pure) + duped Ghosts Modest (82.5) + Stormy Batter's Helmet (~18) + ~1 in other items

Seller:

http://backpack.tf/profiles/76561198055358018?time=1433487600 (June 5th)

http://backpack.tf/profiles/76561198055358018?time=1433574000 (June 6th)

Luger + Modest: http://www.tf2outpost.com/trade/26139999

Ballcap: http://backpack.tf/item/710788993

The Luger sold easily for 200 pure, so it can be valued as pure. Batter's is valued at lower-end since it's outdated slightly, and the duped Ghosts Modest is valued at normal price, it should be fairly close.

Items received: http://i.imgur.com/Srs8OjC.png (Luger is missing because it was traded for 200 pure on the same day)

(200) + ((82.5 + 18 + 1) * 0.9) = 291.35; rounded to 290 keys

Duped Sparkle Lugermorph:

http://www.tf2outpost.com/trade/26140933 Sold to puddington for 200 pure

Including the sale at 370 from the last suggestion the range would be 250-370 with these new sales.