Free Suggestion!

Copy pasted from other suggestion

Seller unsold @ 30 for 1 month and young seller @ 20:

https://imgur.com/a/618AMEg

https://backpack.tf/item/3992747583

Sale 1) ?

https://backpack.tf/profiles/76561197989281781#!/compare/1528675200/1528761600

Sale 2) Bulk

https://backpack.tf/profiles/76561198048492330#!/compare/1530403200/1530489600

Sale 3) ?

https://backpack.tf/profiles/76561198052431073#!/compare/1531526400/1531699200

Sale 4) ?

https://backpack.tf/profiles/76561198158607141#!/compare/1531699200/1531785600

Sale 5 - 6) Sold for $60 when Keys were ~$1.95 each and $40 when keys were $1.9 each

https://marketplace.tf/items/15058;15;u704;w2;pk58;kt-3

60 / 1.95 = ~31 Keys

40 / 1.9 = ~21 keys

Sale 7) Bulk

https://backpack.tf/profiles/76561198081495160#!/compare/1533600000/1533686400

Sale 8) Sold to a Buy Order

https://backpack.tf/profiles/76561198030343929#!/compare/1533600000/1533686400

https://backpack.tf/profiles/76561198030343929#!/compare/1533600000/1533686400

Sale 9 - 15 keys

https://backpack.tf/profiles/76561198013460777#!/compare/1534982400/1535068800

https://backpack.tf/profiles/76561197994587943#!/compare/1535068800/1535155200

Sale 10 - Untraceable

https://backpack.tf/profiles/76561198084574795#!/compare/1534464000/1534550400

https://backpack.tf/profiles/76561198097150194#!/compare/1534464000/1534550400

Sale 11 -Untraceable

https://backpack.tf/profiles/76561198059424894#!/compare/1534464000/1534550400

https://backpack.tf/profiles/76561198097150194#!/compare/1534464000/1534550400

Summary

Sales are 15, 21, and 31

Excluding 31 due to unsold at 30 for 1 month and seller at 20

Taking 15-21!