Phone suggestions are hard.

https://backpack.tf/item/4388888090

Sale 1) Sold for a Max's Severed Head (~18 Keys)

https://backpack.tf/profiles/76561198151598896#!/compare/1498089600/1498176000

Low Outlier.

Sale 2) Sold for a Planets Falkirk (23 Keys) + ~7 Keys of Items

https://backpack.tf/profiles/76561198160909941#!/compare/1499040000/1499299200

23 + 7 = 30 Keys

https://backpack.tf/item/3499325670

Sale 3) Sold for 23 Keys

https://backpack.tf/profiles/76561198046921199#!/compare/1496016000/1496188800

Sale 4) Sold for 26 Keys

https://backpack.tf/profiles/76561198015384426#t5832965226

Took 1 Day.

Sale 5) Sold for a Skill Gotten Gains Party Trick

https://backpack.tf/profiles/76561198084253260#!/compare/1496361600/1496620800

Either a high outlier here or can be used to update that.

Sale 6) Sold for 24 Keys

https://backpack.tf/profiles/76561198175249965#!/compare/1499558400/1499644800

Sale 7) Sold for a Green Confetti Cosa Nostra Cap (32 Keys)

https://backpack.tf/profiles/76561198095320741#!/compare/1500249600/1500336000

Including 26 in the range because of lower sales, but excluding the lower ones because 26 was a quicksell.