If your suggestion fails due to extra sales/faulty range or something, can you at least try to resuggest without leaving it closed

Sale 1

http://www.tf2outpost.com/trade/27305717 Sold with 1.1 keys of sweets and 7 keys for DBD Milkman

B/O for Milk was 25

Presumed Trilby was offered

X + 1.1 + 7 = 25

X = 17

Milk http://backpack.tf/item/2385699721

Trilby http://backpack.tf/item/1742990428

Sale 2

http://www.tf2outpost.com/trade/27389954 Sold for Pro KS Aussie Tomi

B/O for Trilby was 19

X = 19.8*0.9

X = 18

Tomi http://backpack.tf/item/2800893127

Flipped http://backpack.tf/item/1627972266

Mini for Tomislav

http://steamcommunity.com/market/listings/440/Strange%20Professional%20Killstreak%20Australium%20Tomislav Sold for $47.61 on Nov 27th

47.61 + 47.61/1.15 = 89.01

89.01/2 = 44.51

Keys were $2.25 at time of sale

44.51/2.25 = 19.8 keys

Sale 3

http://www.tf2outpost.com/trade/27323061 Sold for P. Fetti Chieftain's + TS Bill's

B/O for Trilby was 21

B/O for Chieftain's was 15

X = 15*0.9 + 2.6*0.9

X = 16

Chieftain's http://backpack.tf/item/342945815

Bills http://backpack.tf/item/280499989

Trilby http://backpack.tf/item/1627972266

Sale 4

http://www.tf2outpost.com/trade/27524675 Sold for 19 keys

B/O for Trilby was 20

X = 19

Trilby http://backpack.tf/item/1028482114

Keys were probably used to buy this http://backpack.tf/item/1527451386 as there are no keys in the backpack after sale

Seller

http://www.tf2outpost.com/trade/27535085 18 keys