I blew out my ACL last Jan, had surgery in Sept and am now just starting to back to skiing/regular activities.  I got my brace through my physio, custom Don Joy Defiance III, short cuff model for skiing, which also happens to be the official knee brace of the US Ski team.  My work insurance (Canadian) covered the whole shebang.  Through my physio it was $1450 for a custom brace and $650/700 for an off the shelf model (s/m/l).  He sized me an everything but the good part at least with Don Joy is that within the first year of getting your brace, if it no longer fits properly (i.e. get fat, slim down, or bulk up) they will send you a new proper fitting brace.