Stephen,
For that amount of money, you are talking a 1988-1992 model boat ... or a trashed later model.
Actually, wakeboard boats had not quite come into their own in that timeframe ... three event skiing was still KING! I should know cause that is when I bought my first new MasterCraft PS190. No such thing as XStars and the like. So finding a factory boat between 1988-1992 with ballast systems and tower will be difficult.
You will likely have to buy a standard comp boat and outfit it accordingly. My folks live on BSL and I make it down there often. They run a 1996 Malibu Tantrum and with a sac it actually makes a sweet wakeboard boat.
There is a guy in Lake St Louis MO (near St. Louis) with a 1993 Ski Nautique for $14500 ... take a look on
http://www.ski-it-again.com, it is posting number SIA01372. I have skied a 1994 CCSN and with some weight it made a good board boat, better than my 93MCPS190. You may also find something else on there to your liking. If not post a WANT AD.
Hope you find something ...
LarryG
Webmaster
SKI-IT-AGAIN.COM