Market is flooded with 4.5 keys. Some sellers already go under so a range is neccesary. Proof:

http://backpack.tf/classifieds/search/527/11/0 7 unsold for 4.5; one for 4.4

Sellers:

http://www.tf2outpost.com/trade/9521823 - 4.5

http://www.tf2outpost.com/trade/9529263 - 4.5

http://www.tf2outpost.com/trade/9465118 - 4.75

http://www.tf2outpost.com/trade/9444216 Unsold for 5; 3 days

http://www.tf2outpost.com/trade/9287811 Unsold for 5; 1 week

http://www.tf2outpost.com/trade/9409053 Unsold for 5; 4 days

http://www.tf2outpost.com/trade/9405164 Selling for 4 plain; 5 days old!

http://www.tf2outpost.com/trade/9507125 Selling for 4 keys, got an "added", but trade is still up.

http://www.tf2outpost.com/trade/9283256 Best offer in one week: ~4 keys

http://www.tf2outpost.com/trade/9275255 Best offer in one week: 4 keys

Buyers:

http://www.tf2outpost.com/trade/9397357 Has 18 in his Bp.Buying for 2.5 (I know, quicksell, but it shows that many people go way lower than curr.)

http://www.tf2outpost.com/trade/9503523 Someone willing to sell for 4

http://www.tf2outpost.com/trade/9341225 Another kinda auction; One person is willing to sell for 4 and he has another 4.75 key offer.

http://www.tf2outpost.com/trade/8647479 Somebody willing to sell for 4

http://www.tf2outpost.com/trade/9509059 Could buy one for 3

http://www.tf2outpost.com/trade/9247540 Another quickbuyer: Has bought alot for 3 keys in one week.

Kinda hard to find alot of proof as almost everyone sells for very highballed prices.

Let the hate begin +_+

Feel free to comment :D