You can get a nice Malibu Sportster for less that $20K, it will even be fairly new! The boat has a lot of potential for wakeboarding when you add the wedge and a lot of weight. I sold my 98 last year for $16,500. You can still pick them up cheap. They are a heck of a boat. Check www.malibuboatowners.com
and see how other people like them.