Credits to Torb for the previous suggestion where the OP skins sale is detailed.

Credits to VeryDoge for the screenshots!

Sale 1 (Torb's):

https://opskins.com/?loc=shop_view_item&item=347100124

Sold for 210$ , https://opskins.com/?loc=shop_search&app=440_2&search_item=%22Mann+Co.+Supply+Crate+Key%22&search_internal=1 keys were 1.79

210/1.79=117.318436 , rounding to 117

Sale 2:

https://backpack.tf/profiles/76561198073522694#!/compare/1530748800/1530921600

https://prnt.sc/k4v1cy

https://prnt.sc/k4v1ry

https://prnt.sc/k4v22e

https://prnt.sc/k4v2fl

https://prnt.sc/k4v2nb

Sold for G Fetti Salty(38.5) + Vivid Naggenvatcher + OF Toy Soldier + ~6 keys in sweets

Soldier Mini:

https://backpack.tf/profiles/76561198325528667#!/compare/1528761600/1528848000

https://backpack.tf/profiles/76561198255850609#!/compare/1528675200/1528848000

Sold with a key for OF Warhood

Warhood Micro:

https://backpack.tf/suggestion/5b43e2eb44325a5e3b75ba04

Suggestion for 15.5 keys

Total is 14.5 keys

Let's take 15 for it.

Naggenvatcher Mini:

https://backpack.tf/suggestion/5b5a15a144325a4b3640a6b6

Suggestion for 31.5 keys

Total is 31.5 + 38.5 + 6 + 15 = 91 keys

https://i.imgur.com/QJtNKx2.png

Seller for 100 keys, no buyers of note.

Lets go with 91 - 117 keys.