x-wave 10, but those are really expensive.  the problem is you wont find a good boot for backcountry for cheap.  You want a pretty stiff boot that will give you a ton of control, and boots generally get more expensive as they get stiffer.  So your only choice if you want to save money is to try to find a pair of boots from last year.  Look for these boots: Salomon X-Wave 10, Salomon 10 Scream, Lange Comp 120 FR, Tecnica Icon Alu, Tecnica Diablo, Nordica Beast 10 or 12