Too late.

Counter.

Sale 1: Untrace.

https://backpack.tf/profiles/76561198299619152#!/compare/1554854400/1556150400

https://backpack.tf/profiles/76561198048851745#!/compare/1554768000/1554940800

Sale 2: Untrace.

https://backpack.tf/profiles/76561198014222399#!/compare/1556841600/1557187200

https://backpack.tf/profiles/76561198002757046#!/compare/1556841600/1556928000

https://backpack.tf/profiles/76561198002757046#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198049322925#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198049322925#!/compare/1556755200/1556928000

https://backpack.tf/profiles/76561198886563850#!/compare/1556668800/1556841600

https://backpack.tf/profiles/76561198886563850#!/compare/1556668800/1556841600

https://backpack.tf/profiles/76561198084095917#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198084095917#!/compare/1556755200/1556928000

https://backpack.tf/profiles/76561198081793950#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198081793950#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198057292706#!/compare/1556755200/1556841600

(Gambling? untrace)

Sale 3: ~12 Keys Pure.

https://backpack.tf/profiles/76561198057292706#!/compare/1557014400/1557100800

https://backpack.tf/profiles/76561198889318461#!/compare/1556928000/1557100800

Sale 4: Use There.

Sold With 3 Keys For Circling Peace Sign Conquistador.

https://backpack.tf/profiles/76561198889318461#!/compare/1557100800/1557187200

https://backpack.tf/profiles/76561198154023527#!/compare/1557100800/1557187200

Sale 5: Bulk.

https://backpack.tf/profiles/76561198154023527#!/compare/1557100800/1557187200

https://backpack.tf/profiles/76561198008994962#!/compare/1557100800/1557187200

Sale 6: Bulk.

https://backpack.tf/profiles/76561198008994962#!/compare/1557187200/1557360000

https://backpack.tf/profiles/76561198133986940#!/compare/1557273600/1557360000

Sale 7: Used there.

Sold With Captain Cardbeard Cutthroat (2.65) + 1 key for Terror-Watt Antarctic Eyewear.

https://backpack.tf/profiles/76561198133986940#!/compare/1557360000/1557446400

https://backpack.tf/profiles/76561198325528667#!/compare/1557360000/1557446400

Sale 8: ~11 Keys Pure.

https://backpack.tf/profiles/76561198325528667#!/compare/1557446400/1557532800

https://backpack.tf/profiles/76561198316724901#!/compare/1557446400/1557532800

Sale 9: ~13 Keys.

Sold For Dead Presidents Crocleather Slouch (12) + 1 Key.

https://backpack.tf/profiles/76561198316724901#!/compare/1557619200/1557792000

https://backpack.tf/profiles/76561198799390049#!/compare/1557619200/1557792000

Marketplace.tf Sale:

https://marketplace.tf/items/399;5;u66

Sale 10: High.

Apr 29

$34.50 / $1.82 = 18.96 keys

Including Sales: 11/12/13

Going With 11-13 Keys.

Thanks to scourge for the premium!

Mini for sale 9:

https://backpack.tf/suggestion/5ce130bf678072693a72954b

Few new sales.

Sale 11: ~12 Keys Pure.

https://backpack.tf/profiles/76561198048851745#!/compare/1558828800/1558915200

https://backpack.tf/profiles/76561198159976008#!/compare/1558828800/1558915200

Sale 12: Seems like ~13 Keys Pure.

https://backpack.tf/profiles/76561198159976008#!/compare/1559692800/1559952000

https://backpack.tf/profiles/76561198063107526#!/compare/1559865600/1559952000

Sale 13: Re-Sold For ~11 Keys Pure?

https://backpack.tf/profiles/76561198063107526#!/compare/1559865600/1559952000

https://backpack.tf/profiles/76561198081270783#!/compare/1559865600/1559952000

Sale 14: ~11 Keys?

https://backpack.tf/profiles/76561198081270783#!/compare/1559952000/1560038400

https://backpack.tf/profiles/76561198047168424#!/compare/1559952000/1560038400 - 11 keys match.