Sale 1:

Sold for 28 keys

Seller: https://backpack.tf/profiles/76561198015384426#!/compare/1506211200/1506297600

Buyer: https://backpack.tf/profiles/76561198089953006#!/compare/1506297600/1506384000

X = 28

Sale 2:

Sold for 26 keys in ~2 days

Seller: https://backpack.tf/profiles/76561198117379982#!/compare/1505433600/1505520000

Buyer: https://backpack.tf/profiles/76561198015384426#!/compare/1505088000/1505606400

X = 26

Sale 3:

Sold for 23 keys + some ref in about a day

Seller: https://backpack.tf/profiles/76561198122604075#!/compare/1505260800/1505347200

Buyer: https://backpack.tf/profiles/76561198117379982#!/compare/1505260800/1505347200

X = 23

Sale 4:

Sold for 22 keys in ~2 days

Seller: https://backpack.tf/profiles/76561198263995096#!/compare/1505174400/1505260800

Buyer: https://backpack.tf/profiles/76561198122604075#!/compare/1505174400/1505260800

X = 22

Sellers:

$52.61: ~21 keys

http://steamcommunity.com/market/listings/440/Unusual%20Peacenik%27s%20Ponytail

Can’t identify the history. I doubt it’s the one from the sales above.

Sales at:

22

23

26

28

Sales below 28 sold quickly, but they are abundant, so I won’t exclude all of them.

Don’t want to use the seller, as I’m unsure of how long it has been up there for.

Going with 26-28.