I'm not sure how popular this opinion is but I kinda like abduction. Looks kinda cool imo.

Sold for 32 Keys and ~2 Keys in Sweets(34 Keys total)

http://backpack.tf/profiles/76561198104497540#!/compare/1490832000/1490918400

Sold for 37 Keys

http://backpack.tf/profiles/76561198017911615#!/compare/1492214400/1492473600

Sold for 35 Keys

http://backpack.tf/profiles/76561198197516958#!/compare/1488844800/1488931200

Sold for a Neutron Star Human Cannonball(34 Keys)

http://backpack.tf/profiles/76561198095236132#!/compare/1488499200/1488585600

Sold with ~1 Key in Sweets for a '72 Fresh Brewed Victory(40 Keys)(39 Keys total)

http://backpack.tf/profiles/76561198160569884#!/compare/1488844800/1489363200

Sold for 39 Keys

http://backpack.tf/profiles/76561198134544837#!/compare/1486598400/1486684800

Sold for 40 Keys

http://backpack.tf/profiles/76561198080179568#!/compare/1489968000/1490054400

Sold for 40 Keys

http://backpack.tf/profiles/76561198170217781#!/compare/1491523200/1491696000

Sold for 34 Keys

http://backpack.tf/profiles/76561198087402437#!/compare/1489536000/1489708800

Sold for 34 Keys

http://backpack.tf/profiles/76561198244206564#!/compare/1490140800/1490227200

Sold for 38 Keys

http://backpack.tf/profiles/76561198080179568#!/compare/1492128000/1492214400

Added 8 Keys for an Australium Pro KS Medi Gun(~38 Keys)(30 Keys total, Outlier)

http://backpack.tf/profiles/76561198066950212#!/compare/1490227200/1490832000

Sold for 37 Keys

http://backpack.tf/profiles/76561198066950212#!/compare/1490832000/1490918400

http://backpack.tf/profiles/76561198100636531#!/compare/1490486400/1491264000

34-40.

Credits to Mindacos for finding the proof. All I did was make the actual suggestion.