Sale #1:

http://www.tf2outpost.com/trade/26180288

Sold with 2 keys + Specialized SF Sticky (~8) for a Power Surge Slope Scopers (25)

http://backpack.tf/profiles/76561198168412865?time=1434265200 (June 14th)

http://backpack.tf/profiles/76561198168412865?time=1434351600 (June 15th)

25 - (8 + 2) = 15 keys (no overpay)

Sale #2:

http://www.tf2outpost.com/trade/26209808

Sold with a Specialized SF Sticky (~8) + 2 keys + Pink Bill's (2) for a Level 1 Max (~23)

http://backpack.tf/profiles/76561198168412865?time=1434351600 (June 15th)

http://backpack.tf/profiles/76561198168412865?time=1434438000 (June 16th)

23 - (8 + 2 + 2) = 11 keys (no overpay)

Sale #3:

Sold with 1 bud (3) for a Peace Sign Softcap (14)

Seller:

http://backpack.tf/profiles/76561198068190834?time=1434092400 (June 12th)

http://backpack.tf/profiles/76561198068190834?time=1434265200 (June 14th)

Buyer:

http://backpack.tf/profiles/76561198058711168?time=1434006000 (June 11th)

http://backpack.tf/profiles/76561198058711168?time=1434265200 (June 14th)

Softcap: http://www.tf2outpost.com/trade/26184639

14 - 3 = 11 keys (no overpay)

Sale #4:

http://www.tf2outpost.com/trade/26148965

Sold for a Skill Gotten Gains I See You (20)

http://backpack.tf/profiles/76561198035884807?time=1434178800 (June 13th)

http://backpack.tf/profiles/76561198035884807?time=1434265200 (June 14th)

Should be an easy outlier.

Sale #5:

Sold with ~4.6 keys in items for a Miami Nights L'homme Burglerre (outdated at 17)

http://backpack.tf/profiles/76561198057445952?time=1428044400 (April 3rd)

http://backpack.tf/profiles/76561198057445952?time=1428130800 (April 4th)

L'homme: http://www.tf2outpost.com/trade/25577127

17 - 4.6 = 12.4 keys

Sale #6:

Sold with a Steaming Noble (19) + ~1 in items for a Vivid Napper's (32)

http://backpack.tf/profiles/76561198035884807?time=1433401200 (June 4th)

http://backpack.tf/profiles/76561198035884807?time=1433660400 (June 7th)

32 - (19 + 2) = 11 keys Supports lower-end