I'm suggesting this price of 53 key low value to 64 keys high value because of these sale made within 1 month 53+64=117/2= 58.5 keys

[He traded the Defiant Spartan 1:1 for a Searing Plasma Wet Works +3 keys that's currently worth 50 key here's the proof of the sale:

http://backpack.tf/profiles/76561198058274919#!/compare/1466294400/1468800000]

[he traded the Defiant Spartan + 10 keys for the salty dog here : http://backpack.tf/profiles/76561198088707185#!/compare/1468108800/1468368000] [PS:I'm not counting the paint on the Salty dog]

Power Surge Defiant Spartan History: http://backpack.tf/item/1655496697

Stormy storm Salty Dog history: http://backpack.tf/item/2003835600

Searing Plasma Wet Works history: http://backpack.tf/item/1985883471

Proof the new owner have the Salty dog and currently selling it : http://www.tf2outpost.com/trade/28334409

Other owner not currently selling the wet works.

Trying to reprice it since it's a price of 2 years ago.

Don't go blaming for the price because these are the only recent sales.

Non duped Power Surge Spartan is not on sale and it's been 2 year of this and still not on sale.

Inventory of the guy with the Non duped: http://backpack.tf/profiles/76561198070102519

I Don't know if the link here http://backpack.tf/profiles/76561198088707185#!/compare/1468108800/1468368000 is glitched for you guy but if it is just put

From: 2016/07/10 and the To: 2016/07/13