The 2002 ZR is worth about $2000-$2500 depending on condition. That 440 ProX is probably woth $2500-$3000. It will whip that 600ZR's ass but is not really for the average rider. High octane only, pre-mix fuel, stiff ass suspension etc. I have a Ski-Doo MXZX 440. Basically the same type of shit to deal with.