Generally considered one of the best all around performance and reliability mtn packages money can buy in snowmobiling.
Obviously depending on maintanance and use 4000 miles is right at the point where this type of vehicle requires some replacement parts which seriously effect the value of the "deal". 4500 miles of use in a maximum of two seasons on a mountain sled is pretty high and it might possibly have been accomplished in 1 season. Most likely from a rental fleet and most rental companies attempt to replace the fleet at 2 seasons and this average mileage. One is mechanical economics and two is marketing by having a new or considered new vehicle to offer in your rental pool. Quite possibly the records of maintanance are available on this sled. If you do your own work you can do most or all minor wear items (track, hyfax, clutching, bearings, chains, misc bushings, and some electrical componants, ect) relatively inexpensively but if you have to have a shop do these things you will quickly be dollars ahead to buy a brand new hold over 09 clear on up to $8500 if the right list of parts needs replacement over it's use span for you.
Remember the engine is one aspect and is easily capable of well over 10,000 miles but that is not necessarily what will get you on this sled. Once again this is an excellent all around platform so if your homework shows this particular sled to be tight and some required stuff already taken care of this would be a good deal. Overall performance of two like stock 09 sleds one 700cc and one 800cc you will not notice a tremendous performance difference. That is the primary reason the 700cc sled is omitted from the 2011 line-up. (also note if you plan on owning this sled for an extended time you are buying a motor system that is being removed from the manufacturers inventory...generally speaking this is years down the road stuff and not a big concern)