Sale at 6 keys 50 ref (6.86 keys) : https://backpack.tf/profiles/76561198305494036#!/compare/1590710400/1590796800

Sales on marketplace.tf: https://marketplace.tf/items/tf2/652;5;u33

Sale on June 20 2020: $18.49 (median key price: $1.98, 18.49/1.98=9.34 keys)

Sale on June 28 2020: $15.59 (median key price: $2.05, 15.59/2.50=7.60 keys)

buy order: $10.00 (taking $1.98 as key price: 10/1.98=5.05 keys)

key prices: https://marketplace.tf/items/tf2/5021;6

The sale at 9.34 keys is too high because there are sellers at 7.6, 8 and 9 keys.

Taking 6.86-7.60 keys as the price range for my suggestion, 7-7.5 keys rounded up

None have recently been bought or sold in the 10-11 keys range so the price needs to be lowered