Shine brighter than a diamond.

https://backpack.tf/item/5469262583

Sale) Sold + Max's (19 Keys) + P. Fetti Skid Lid (18 Keys) + Collector's Pro KS Back Scatter (~10 Keys) for a Duped Arcana Bonk Boy (326 Keys)

https://backpack.tf/profiles/76561198027544408#!/compare/1492646400/1492732800 - Seller's Backpack

https://backpack.tf/profiles/76561198102469410#!/compare/1492646400/1492732800 - Buyer's Backpack

326 - 19 - 18 - 10 = 279, which I'll round to 280 Keys

Skid Lid Mini

https://backpack.tf/suggestion/59060de8c4404559904d7deb - 18 Keys

Bonk Mini

Sold + Spec KS Aussie Tomislav (~12 Keys) for a Green Energy Winter Woodsman (282.5 Keys) + Frostbite Smoking Skid Lid (55.5 Keys)

https://backpack.tf/profiles/76561198287496233#!/compare/1487376000/1487548800

282.5 + 55.5 = 338 - 12 = 326 Keys

http://www.tf2outpost.com/trade/28824529 - 1 Month Unsold at 350 Keys (6 Months at 360 on Classifieds)

http://www.tf2outpost.com/trade/28841809 - 1 Month Unsold at 355 Keys

http://www.tf2outpost.com/trade/28874916 - 2 Week Unsold at $600 on Marketplace, which is under 300 Keys with the current Key price ($2.08)