http://backpack.tf/classifieds/?item=Machina&quality=11&tradable=1&craftable=1 – Plenty for 17 Keys

16 Keys:

http://www.tf2outpost.com/trade/22446060

17 Keys:

http://www.tf2outpost.com/trade/22459066 - I just got this for 17 keys and its spec ks and has parts

http://www.tf2outpost.com/trade/22428598 - 1 day

http://www.tf2outpost.com/trade/22424564 - 2 days

http://www.tf2outpost.com/trade/22418605 - 2 days autobump

http://www.tf2outpost.com/trade/22376369 - 4 days autobump

http://www.tf2outpost.com/trade/22315318 - 1 week

18 Keys:

http://www.tf2outpost.com/trade/22443369 - 1 day + spec ks

http://www.tf2outpost.com/trade/22419252 - 2 days + spec ks

http://www.tf2outpost.com/trade/22415754 - 2 days autobump

http://www.tf2outpost.com/trade/22411500 - 3 days autobump

http://www.tf2outpost.com/trade/22392883 - 4 days

http://www.tf2outpost.com/trade/22377767 - 4 days

http://www.tf2outpost.com/trade/22354614 - 5 days

http://www.tf2outpost.com/trade/21812148 - 4 weeks autobump

Pretty much most of these have parts - and the rest on the market are asking for a bud + or have ks parts