Albert Einstein, but on fire. When an an experiment goes wrong this occasionally occurs. Take 2.

One sale on January 12th 2019 on mp.tf at $650: https://marketplace.tf/items/590;5;u13

https://manic.tf/keyprice/?at=2019-01-12 keys worth $1.75 on that day, $650 / $1.75 = 371.43 keys

1:1 swap earlier (2/2/19) with a Misty Skull Blighted Beak: https://backpack.tf/stats/Unusual/Blighted%20Beak/Tradable/Craftable/44

Proof: https://backpack.tf/profiles/76561198070664972#!/compare/1546646400/1549065600 (not that it matters, you'll see why later)

Sold for 325 pure a little while after that sale (so also 2/2/19)

Proof: https://backpack.tf/profiles/76561198070664972#!/compare/1549065600/1549152000

Yes, these two trades happened in the same day. Life is one hell of a ride.

Discussion on usable sales: first trader/user did not care about the value of the Flames Braniac, they purely wanted the Misty Skull Beak to match one of their Medic Unusuals. For this reason I will exclude the exchange and thus ignore adding a lower boundary of 230 keys, as this range would be far too large anyways. Third sale also deemed unusable (thanks Torb) as it was technically sold to a quickbuyer, and in a very short timespan. For this reason only the marketplace.tf order will be used.

372 keys rounds towards 370. Other sales are provided as future reference for any new price suggestions made after this one.

Thanks to TF2Scourge and Wild_Rushn for help finding any alternate sales.