Bot.tf doesn't track sales properly. It just takes the listed price when the item was traded. You have to trace the trade with compare links for it to be valid. Otherwise, it's just a normal untrace sale.

new sales:

https://marketplace.tf/items/tf2/30542;5;u33

$39.99 / $1.93 = 20.72 keys <--- likely https://backpack.tf/item/8892955281

$41.9 / $1.92 = 21.82 keys <--- https://backpack.tf/item/3365201717 (Erik had a B/O of 20 keys, capping)

https://backpack.tf/profiles/76561197964171516#!/compare/1597017600/1597104000

https://backpack.tf/profiles/76561198102185053#!/compare/1597017600/1597276800

Sold for 20 keys (batched with 18 that were not part of sale)

https://backpack.tf/profiles/76561198102185053#!/compare/1597017600/1597276800

https://backpack.tf/profiles/76561198115510029#!/compare/1597276800/1597363200

Sold for 15 keys (8 used to buy Executioner)

under buyers / at buyers

given that 22 is capped at 20, I'd say calling 21 the slight outlier is fine.

Clapped Out does have a point about bot.tf. please include the compares linked to each sale, for next time. (clicking on the date of the sale in bot.tf will open a compare)

as for Clapped Out's comment on scrap selling a OF Coldsnap for ~18 keys, I'm unable to trace any OF Coldsnap being in Scraprehensve's inventory during that time, so it likely was there for a very short amount of time.

given that the scrap sale was likely very fast, this should be fine.