Marketplace Sales:

https://marketplace.tf/items/tf2/30399;5;u57

$19.99, April 8th

$17, May 1st

No snapshots available

https://backpack.tf/item/7956867273 - April 8th

Can’t find the other history.

https://manic.tf/keyprice/?at=2020-04-08&price=19.99 - $19.99 / $1.69 = 11.83 keys

http://manic.tf/keyprice?at=2020-05-01&price=17 - $17 / $1.85 = 9.19 keys

After rounding, we have:

12 keys

Other Sales:

https://backpack.tf/item/7957393274 - gambled, or otherwise unusable

Sellers:

https://i.imgur.com/oJj51qy.png

https://backpack.tf/item/7957393274 - 16 keys

https://marketplace.tf/items/tf2/30399;5;u57

https://backpack.tf/item/7956867273 - $30 (~16 keys)

https://backpack.tf/item/7956317427 - $31 (~17 keys)

Sales at:

9

12

Taking 9-12.

https://i.imgur.com/8YsQcph.png - may want to wait a bit before accepting/reviewing the suggestion

Edit: sold

https://backpack.tf/profiles/76561198050582650#!/compare/1589068800/1589155200

nuts dragonborn + ~8 keys in pure/items, should cap at 16 keys. Might be better to leave outdated, sales are pretty far apart now.