Originally posted by: Zenmervolt
If your main desire is to pull tubers or skiers on the cheap, I would recommend a small jet boat rather than a jet ski.
That said, jet boats and jet skis lack the ability to "pop" a skier right out of the water the way that a propeller-driven boat can and will tend to drag a skier a bit more before they get up. Also, since they lack central tracking chines and have the tow eye located on the transom instead of on a center post inside the boat, they tend to get pulled from side to side if you are pulling a slalom skier.
If you really want to ski and tube, your only really good option is an inboard, prop-driven, ski boat like a Correct Craft Ski Nautique or a Master Craft ProStar. I grew up with Ski Nautiques, so my own bias lies in that direction. And I'll also admit to a bias against using jet boats (or any jet-propelled watercraft) as a tow vehicle.
ZV