Thanks to Eldric Liaz for finding more sales.

There were 2 recent sales for the strange GE Peak.

Sale 1: 171 keys

https://marketplace.tf/items/30743;5;u9;strange

https://backpack.tf/item/4594374051

Sales at $325 during Feb 1st.

Key sold for 1.9 keys during February 1st: https://web.archive.org/web/20180228200526/https://marketplace.tf/items/5021;6/Mann%20Co.%20Supply%20Crate%20Key

so 325/1.9 = roughly 171 keys

Sale 2: 220 keys

Sold for Tesla Coil Crone's Dome (150) + 70 keys pure = 220 keys in total

https://backpack.tf/profiles/76561198069950258#!/compare/1524960000/1525132800

Seller had a b/o of 220 keys:

http://www.tf2outpost.com/trade/29503020

Tesla Coil Crone's Dome is in-date:

https://backpack.tf/suggestion/5a724015cf6c751f9b536917

Thanks!