Challenge 19, Team F.L.A.M.B.E.S!

39th suggestion, made by Mikey!

Sale 1:

https://marketplace.tf/items/tf2/30615;5;u3015

Cannot find item history.

May 26th - $49.99

Keys were $1.93 that day, so 49.99 / 1.93 = 25.9 keys, rounding to 26.

https://bot.tf/stats/listings/4O9WJ6WG B/O of 20 keys, capping

Sale 2:

https://marketplace.tf/items/tf2/30615;5;u3015

https://backpack.tf/item/5231162559

June 26th - $49.99

Keys were $2.03 that day, so 49.99 / 2.03 = 24.63 keys, rounding to 25.

Sale 3:

https://backpack.tf/profiles/76561198340634356#!/compare/1587168000/1587254400

https://backpack.tf/profiles/76561198823319707#!/compare/1587168000/1587254400

17 keys pure

Sale 4:

https://backpack.tf/profiles/76561198096856475#!/compare/1588464000/1588636800

https://backpack.tf/profiles/76561198045968907#!/compare/1588032000/1588550400

16 keys pure

Summary of Sales:

1 @ 16 keys

1 @ 17 keys

1 @ 25 keys

1 @ 20 keys

One unsold on classifieds @ 17 keys for 4 months, invalidates both higher sales.

Taking 16-17 keys.