Sale 1

Appears to have sold with 1 key for strange spec killstreak festive knife (16 keys) = 16 - 1 = 15 keys

Buyers bp before: http://backpack.tf/profiles/76561198096438357?time=1428044400

Buyers bp after: http://backpack.tf/profiles/76561198096438357?time=1428130800

Sale 2

Looks like it sold for an aussie sniper (36-40 keys)= 38 * 0.9 = 34 keys - outlier... I feel like I'm missing something on this sale but can't figure out anything else involved in the trade

Sellers bp before: http://backpack.tf/profiles/76561198096438357?time=1428217200

Sellers bp after: http://backpack.tf/profiles/76561198096438357?time=1428303600

Sale 3

Appear to have sold for genuine horace (9 keys at time) + 6 keys = (9 * 0.9) + 6 = 14 keys

Sellers bp before: http://backpack.tf/profiles/76561198125450627?time=1427408105

Sellers bp after: http://backpack.tf/profiles/76561198125450627?time=1427526000

Sale 4

Appears to have sold for kill-a-watt swagman's swatter (15-23 keys) = 19 * 0.9 = 17 keys

Buyers bp before: http://backpack.tf/profiles/76561198058278295?time=1422604800

Buyers bp after: http://backpack.tf/profiles/76561198058278295?time=1422691200

Some sales inbetween that I couldn't track / figure out

Mini for strange spec ks festive knife:

~£20 on scm at time of sale

refined 0.08 each at time

20/0.08 = 250 refined

keys 16 refined at time

250/16 = 15.62 = ~16 keys

Not sure if that's the correct way to price killstreaks but made sense to me.

Feedback welcome!