I did forget for a day o-o

Sale 1: https://backpack.tf/profiles/76561198259242019#!/compare/1587168000/1587340800

https://backpack.tf/profiles/76561198002757046#!/compare/1585180800/1585267200

?

Sale 2: https://backpack.tf/profiles/76561198002757046#!/compare/1585267200/1585353600

https://backpack.tf/profiles/76561198171624643#!/compare/1585267200/1585353600

20 pure.

Sale 3: https://backpack.tf/profiles/76561198171624643#!/compare/1585872000/1586044800

https://backpack.tf/profiles/76561198378320706#!/compare/1586044800/1586217600

Sold for a Circling Heart Bottle Cap (buy orders at 9.65: https://i.imgur.com/i4b8aws.gifv ) + 16 pure + ~4.67 in items, taking buy orders: https://i.imgur.com/BmdWOYR.png + https://i.imgur.com/uPFHCpk.png

9.65 + 16 + 4.67 = 30.32, buyout was 30: https://bot.tf/stats/listings/4290K387

Sale 4: https://backpack.tf/profiles/76561198378320706#!/compare/1586304000/1586563200

https://backpack.tf/profiles/76561198408017461#!/compare/1586304000/1586476800

Use there.

Sale 5: https://backpack.tf/profiles/76561198408017461#!/compare/1586563200/1586649600

https://backpack.tf/profiles/76561198095022965#!/compare/1586563200/1586649600

Use there.

Sale 6: https://backpack.tf/profiles/76561198095022965#!/compare/1587254400/1587340800

https://backpack.tf/profiles/76561198259242019#!/compare/1587168000/1587340800

35 pure.

Additional by Blaze:

new sales:

https://marketplace.tf/items/tf2/31042;5;u9 - $41.99 (22 keys)

https://backpack.tf/profiles/76561198202672367#!/compare/1589760000/1589846400

https://backpack.tf/profiles/76561198101915413#!/compare/1589760000/1589846400 - sold for 21~ keys

https://backpack.tf/profiles/76561198305494036#!/compare/1589587200/1589673600

https://backpack.tf/profiles/76561198202672367#!/compare/1589587200/1589673600 - sold for 21~ keys

https://backpack.tf/profiles/76561198291041323#!/compare/1589328000/1589673600

https://backpack.tf/profiles/76561198305494036#!/compare/1589587200/1589673600

https://bot.tf/stats/listings/MXX8DW0D - sold to buy-order (19~ keys)

https://backpack.tf/profiles/76561198002757046#!/compare/1587600000/1587686400

https://backpack.tf/profiles/76561198088822281#!/compare/1587686400/1587772800 - sold for 22 keys

ignoring sales from last suggestion as they are outdated, we have sales at 19, 20, 21, 21, 22, 22, 30, 35

the sales at 30+ look high now

aswell as

the sheer amount of new lower sales is a strong indicator that 30 and 35 are high here.

given the buyers at 19+ i'm fine with excluding both lower and higher sales resulting in a range of 21-22 keys

21-22 it is!