"Theres many sales all over the place, but I am excluding the highest ones because of the month old 23 key seller. And excluding the lowest as theres multiple buyers at 13 keys!

http://steamcommunity.com/market/listings/440/Strange%20Haunted%20Beep%20Man - 10 sales between 38€ snd 43€ with multiple sales at both in the latest month.

(TF2 keys are ~2.1€ on the market)

38 / 2.1 = 18 keys (low end). 43 / 2.1 = 20.5 keys, rounding down to 20 keys flat for a good final price of 19 keys!

Going with 18 - 20 keys!" - From my last suggestion.

"Marketplace has a sale at $35(~17 Keys), and a 1+ month unsold at that price: https://marketplace.tf/items/30509;13;strange

Another sale:

Sold for 13 Keys(Countered by SCM quickbuyers)

https://backpack.tf/profiles/76561198257660269#!/compare/1498953600/1499040000

Sold for an Australium Wrench(18 Keys)*

https://backpack.tf/profiles/76561198155168899#!/compare/1495670400/1495756800

*The wrench was immediately resold to scrap.tf for 17 keys: https://backpack.tf/profiles/76561198257660269#!/compare/1495670400/1495756800

SCM sales should not be used for this, moreso when the most recent sales all end up going to quickbuyers. Resuggest at 17-18." - Mindacos in the comments.

So yeah.. Re-suggesting at 17-18 keys