Highest offer i saw was 2.5 keys and lowest buyout was 2 keys. This range seems right now.

Selling 3 keys

http://www.tf2outpost.com/trade/12784492 - Unsold 9 hours

http://www.tf2outpost.com/trade/12771355 - Unsold 18 hours

http://www.tf2outpost.com/trade/12780823 - Unsold 12 hours

http://www.tf2outpost.com/trade/12751387 - Unsold 1 day

http://www.tf2outpost.com/trade/12778526 - Unsold 14 hours

http://www.tf2outpost.com/trade/12780653 - Unsold 12 hours

http://www.tf2outpost.com/trade/12782351 - Unsold 11 hours

http://www.tf2outpost.com/trade/12775275 - Unsold 16 hours

http://www.tf2outpost.com/trade/12772504 - Unsold 18 hours

http://www.tf2outpost.com/trade/12615164 - Unsold 4 days!!

http://www.tf2outpost.com/trade/12788127 - Unsold 5 hours

http://www.tf2outpost.com/trade/12793886 - Unsold 1 hour

http://www.tf2outpost.com/trade/12750088 - Unsold 1 day

http://www.tf2outpost.com/trade/12750124 - Unsold 1 day

http://www.tf2outpost.com/trade/12784916 - Unsold 8 hours

http://www.tf2outpost.com/trade/12791964 - Unsold 2 hours

Selling 2.7 keys

http://www.tf2outpost.com/trade/12784061 - Unsold 9 hours

Selling 2.5 keys

http://www.tf2outpost.com/trade/12780970 - Unsold 12 hours (also lvl 42!!!!!!)

http://www.tf2outpost.com/trade/12567357 - Unsold 5 days!!!

http://www.tf2outpost.com/trade/12795553 - Unsold 1 hour

http://www.tf2outpost.com/trade/12795475 - Unsold 1 hour

http://www.tf2outpost.com/trade/12782376 - SOLD

Selling 2.4 keys

http://www.tf2outpost.com/trade/12784999 - Unsold 8 hours

http://www.tf2outpost.com/trade/12777534 - Unsold 14 hours

Selling 2.3 keys

http://www.tf2outpost.com/trade/12788566 - Unsold 5 hours

Selling 2 keys

http://www.tf2outpost.com/trade/12785244 - Unsold 8 hours

http://www.tf2outpost.com/trade/12758130 - SOLD 1 not other

http://www.tf2outpost.com/trade/12607845 - SOLD

http://backpack.tf/classifieds/search/cat - More 2s and 2.5s