Dont bother... for one polaris is eh... not the worst but not the best. Me and my aunt went in on a '97-98 Yamaha Waverunner, forget how many hours, around 120 maybe? Paid$3000 for it and trailor. Had a few problems but nothin I couldnt fix (I didnt have any experiance on motorcycle / waverunner engines either).
Like anything else, shop around. Check for oil leaks, find out how much oil it burns per outing, and check the cables (accelorator trigger, reverse/drive cable (connects to the "water exhaust" which directs the water in order to propel you forward or back.)
Which ever you decide on their a blast, enjoy!