1 month old price. This item doesn't have many sellers at 4.5 keys anymore but it is still possible to sell one for that. 4 keys is becoming a much more common selling price.

PROOF:

Sellers/sold under 4.5 keys:

http://www.tf2outpost.com/trade/16853318 (4 keys)

http://www.tf2outpost.com/trade/16741460 (4 keys)

http://www.tf2outpost.com/trade/16827533 (4 keys)

http://www.tf2outpost.com/trade/16822149 (4 keys)

http://www.tf2outpost.com/trade/16697259 (4 keys)

http://www.tf2outpost.com/trade/16693294 (4 keys)

http://www.tf2outpost.com/trade/16740978 (4 keys 2 ref)

http://www.tf2outpost.com/trade/16831709 (4 keys 2 ref)

http://www.tf2outpost.com/trade/16803759 (4 keys 3 ref)

http://www.tf2outpost.com/trade/16824761 (4 keys 3 ref)

http://www.tf2outpost.com/trade/16834115 (4 keys 3 ref)

http://www.tf2outpost.com/trade/16793840 (4 keys 3 ref)

http://backpack.tf/classifieds/search/id/52018f91ba2536576300001d

(x4 @ 4 keys at bp.tf classifieds)

Sellers/sold @ 4.5 keys:

http://www.tf2outpost.com/trade/16536133

http://www.tf2outpost.com/trade/16797656

http://www.tf2outpost.com/trade/16850537

http://www.tf2outpost.com/trade/16806964 (1;1 w/ G. Sharp Dresser [4.5 keys])

http://www.tf2outpost.com/trade/16451333 (bp.tf price)

http://www.tf2outpost.com/trade/16795471

http://www.tf2outpost.com/trade/16211406

http://bazaar.tf/trade/584976

http://backpack.tf/classifieds/search/id/52018f91ba2536576300001d

(x1 @ 4.5 keys on bp.tf classifieds)

Feel free to add more proof or counter-proof if you find any and thanks for voting!!