More of a refresh than a suggestion I guess, but doesn't hurt. Three recent sales I could track:

Sale 1

Sold for 7 keys + painted bruiser's bandana (~1.2), just calling this one 8 keys

Sellers bp before: http://backpack.tf/profiles/76561198145046993?time=1426230000 (March 13th)

Sellers bp after: http://backpack.tf/profiles/76561198145046993?time=1426662000 (March 18th)

Sale 2

Sold for 11 keys plus 18 ref = 12 keys

Buyers bp before: http://backpack.tf/profiles/76561198142342087?time=1428822000 (April 12th)

Buyers bp after: http://backpack.tf/profiles/76561198142342087?time=1428908400 (April 13th)

Sale 3

Sold for a massed flies batter's helm = 11 * 0.9 = 10 keys

Sellers bp before: http://backpack.tf/profiles/76561198027711900?time=1427871600 (April 1st)

Sellers bp after: http://backpack.tf/profiles/76561198027711900?time=1427958000 (April 2nd)

Mini for flies batter's helm:

Sold for 11 keys pure

Buyers bp before: http://backpack.tf/profiles/76561198097165073?time=1428908400 (April 13th)

Buyers bp after: http://backpack.tf/profiles/76561198097165073?time=1428994800 (April 14th)