Sale #1:

http://i.imgur.com/MMJxME3.png

Sold for Galactic Codex Sucker Slug (suggestion at 120), Nuts n' Bolts Crown of the Old Kingdom (mini at 126), Nuts n' Bolts Front Runner (mini at 19)

120 + 126 + 19 = 265 Keys

Sale #2:

http://www.tf2outpost.com/user/773890

http://www.tf2outpost.com/user/500785

http://www.tf2outpost.com/item/440,4497673591,30653,5

http://www.tf2outpost.com/item/440,4468899177,539,5

http://www.tf2outpost.com/item/440,4468899173,30553,5

Sold for a Duped Secret to Everybody El Jefe (250) and a Harvest Moon Condor Cap (258.5 mini)

This sale would make for an insane range, but it is capped at 300 Keys because of B/O:

http://www.tf2outpost.com/trade/27365336

Mini:

Front Runner - Seller at 19 Keys ( http://backpack.tf/classifieds?item=Front+Runner&quality=5&tradable=1&craftable=1&particle=31&australium=-1 )

Nuts n' Bolts Old Kingdom - DedAndrei sold his for a Secret to Everybody Milkman (mini at 115), 9 Keys pure, and a ~2 Key skin.

http://imgur.com/xBKLlmb

http://backpack.tf/profiles/76561198125791160/#!/compare/1458284400/1458370800

Only 4 of the keys show up in the links, but DedAndrei let me know he sold it with 9 pure, and will hopefully provide a screenshot later.

115 + 9 + 2 = 126 Keys

Milkman - Sold with Spec KS Aussie Scattergun + Earbuds for a Scorching Yellow Belt http://backpack.tf/profiles/76561198114006087/#!/compare/1455868800/1455955200

157 - 39 - 2.6 = 115.4 ~= 115 Keys

Condor Cap- Declined 258.5 Key offer

http://www.tf2outpost.com/trade/27808327