Sale 1:

https://backpack.tf/profiles/76561198830486882#!/compare/1567036800/1567123200

https://backpack.tf/profiles/76561197994697258#!/compare/1566950400/1567036800

Bulky QS

sale 2:

https://backpack.tf/profiles/76561197994697258#!/compare/1569024000/1569110400

https://backpack.tf/profiles/76561198339075653#!/compare/1550620800/1569110400

Untrace

sale 3:

https://backpack.tf/profiles/76561198339075653#!/compare/1569974400/1571270400

https://backpack.tf/profiles/76561198342161127#!/compare/1569888000/1569974400

QS

sale 4:

https://backpack.tf/profiles/76561198260692541#!/compare/1566086400/1566604800

https://backpack.tf/profiles/76561198115069320#!/compare/1566086400/1567036800

Sold for CTFL Counter + 12 keys

Counter Mini:

https://backpack.tf/suggestion/5dcb5fe46780727cbe3fedf3

Suggestion for 7.5 keys

Total is 19.5 keys

https://bot.tf/stats/listings/Y7DQJK59

B/O of 20 keys

Sale 5:

https://backpack.tf/profiles/76561198115069320#!/compare/1567036800/1567123200

https://backpack.tf/profiles/76561198342161127#!/compare/1566950400/1567036800

Sold for Tw Modest Scrap(14)

Sale 6:

https://backpack.tf/profiles/76561198377165880#!/compare/1566864000/1566950400

https://backpack.tf/profiles/76561198171707301#!/compare/1566864000/1566950400

untrace

Sale 7:

https://backpack.tf/profiles/76561198171707301#!/compare/1568937600/1569196800

https://backpack.tf/profiles/76561198190714350#!/compare/1569110400/1569196800

Bulk

sale 8:

https://backpack.tf/profiles/76561198190714350#!/compare/1569196800/1569283200

https://backpack.tf/profiles/76561198116262699#!/compare/1569196800/1569283200

Sold for 15 keys

Sale 9:

https://backpack.tf/profiles/76561198361490146#!/compare/1572048000/1572134400

https://backpack.tf/profiles/76561198178139659#!/compare/1572048000/1572134400

Untrace

Sale 10:

https://marketplace.tf/items/tf2/340;5;u11

$33.99 / $1.83 = 18.57 keys <--- https://backpack.tf/item/474359891

$23.6 / $1.80 = 13.11 keys <--- https://backpack.tf/item/474359891

Total sales @:

13, 14, 15, 19, 19.5 keys

buyers up to 11 keys,

unsold for 18 keys,

19 key sale resold for 13 later on,

gonna go with 13 - 15 keys, calling 19+ outleirs based on reselling for lower.