Why are there that much vintages that needed to be bumped?

Sellers:

Selling @ less than 1.2 keys:

http://www.tf2outpost.com/trade/12876738 - 5 ref

http://www.tf2outpost.com/trade/13238955 - 1 key

http://www.tf2outpost.com/trade/13211481 - 1 key

http://www.tf2outpost.com/trade/13027721 - 1 key

http://www.tf2outpost.com/trade/13138887 - 1 key

http://www.tf2outpost.com/trade/13148582 - 1.1 keys

Selling @ 1.2 keys:

http://www.tf2outpost.com/trade/13239468 - 2 days ago

http://www.tf2outpost.com/trade/13105307 - 1 week ago

http://www.tf2outpost.com/trade/12668340 - 2 weeks ago

http://www.tf2outpost.com/trade/13163998 - 5 days ago

http://www.tf2outpost.com/trade/13309196 - 12 hours ago

http://www.tf2outpost.com/trade/13205994 - 3 days ago

Selling @ 1.4 keys:

http://www.tf2outpost.com/trade/12659289 - 2 weeks ago

http://www.tf2outpost.com/trade/12849814 - 2 weeks ago

http://www.tf2outpost.com/trade/13212154 - 3 days ago

http://www.tf2outpost.com/trade/13280173 - 1 day ago

http://www.tf2outpost.com/trade/13246669 - 2 days ago

Counter-proof and other typical suggestion for me is welcome. Good Luck and Happy Trading.