i was told about 65 bucks per shock from the guy i bought mine from used. never looked into it as they ended up being fine. i think theyre in nor-cal? someone correct me if i'm wrong but factor in shipping. good luck!
Dont plan on rebuilding them yourself unless you want to buy a 200$ fill valve. They use that special N2 port so unless you know someone with it you will have to buy the tool to refill them with N2. I though about trying to put a regular shrader valve in but I didnt want to mess my shocks up over it. Also Ive been told polaris uses that n2 port so maybe try a quad snowmobile shop to see if they could fill it after the rebuild? I never checked that I was just told.