I have a lot of questions. First, I'm about to look at two boats a 1997 Challenger & 1998 Sportster. The challenger has a bad seal, which causes oil in the cylinder, it does not have an hour meter,he is asking 4,300. Second the sportster has 800hrs,but the boat is in very nice shape. Hes asking 6,500. I,m not familiar with jet boats, How much would it cost to fix the seal? Are these boats dependable? How long before the motors need to be rebuilt? I hear parts and labor are extremely expensive? Am I better off buying a bowrider with a car motor?