Sale 1:

Sold for Death at Dusk Gilded Guard (mini at 45+ below) + Orbiting Fire Barnstormer + ~4 keys in items

http://www.tf2outpost.com/trade/29543708 - B/O of 60

Seller: https://backpack.tf/profiles/76561198129088942#!/compare/1517788800/1518220800

Buyer: https://backpack.tf/profiles/76561198080953509#!/compare/1518134400/1518307200

X = 60 (Capped by B/O)

Sale 2:

Sold for 50 keys

Seller: https://backpack.tf/profiles/76561198048792033#!/compare/1518739200/1518825600

Buyer: https://backpack.tf/profiles/76561198090147535#!/compare/1518739200/1518825600

X = 50

Gilded Guard Mini:

Quicksold for 45 keys

Seller: https://backpack.tf/profiles/76561198163155444#!/compare/1520726400/1520812800

Buyer: https://backpack.tf/profiles/76561198128271841#!/compare/1520726400/1520812800

Not suitable for a suggestion because it’s a quicksell, but it should prove that the sale with this hat should cap at the B/O.

Sellers:

75 keys:

http://www.tf2outpost.com/trade/29602383

Sales at:

50

60

Going with 50-60.