After using these something like 20 times, they are kinda useless...

scrap.tf sells at 7.88: https://scrap.tf/items (not main proof, of course)

Classifieds now: http://backpack.tf/stats/Unique/Backpack%20Expander/Tradable/Craftable

Classifieds at time of posting:

8 ref - x3

8.22 - x1

8.44 - x2

8.66 - x2

Sellers at 8 ref:

http://www.tf2outpost.com/trade/27618693

http://www.tf2outpost.com/trade/27599107 - Sold 3, 1 Week old (May have sold 1 or 2 for 8.33, but I'm in a rush so I can't check

http://www.tf2outpost.com/trade/27624746

Sellers at 8.33:

http://www.tf2outpost.com/trade/27643304 - 1 Sold, 1 Day

Sellers at 8.55:

http://www.tf2outpost.com/trade/23772604

Unsolds at 9 ref:

http://www.tf2outpost.com/trade/27622817 - Non sold, 6 Days

Buyers at 8 Ref and lower:

http://www.tf2outpost.com/trade/23772604 - Same as the 8.55 seller, has 25 in his invintory

Any extra proof accepted, I can't provide much right now because of my garbage internet.