i would say that 28-G for an 03 XTi is a decent price depending on the hours and the overall condition of the boat & don't forget the add-on's such as trailer, type of tower, stereo set up, wedge, perfect pass etc that may or may not make that price a little more appealing.
depending on you level of riding, this boat might not be ideal choice...as it would not be the boat of choice for advanced riders.
Personally, I love my 03XTi.....especially when weighted correctly. We have even had comments that our wake was better and more fun than some of the 21 and 23ft V drives currently market ( Malibu / Nautique / Mastercraft excluded). It offers plenty of seating space = to that of a V Drive, handles great, and planes out very quickly.
Bottom line, the 21XTi is not your average direct drive boat, as those who have ridden behind one would attest to.
just my 2 cents....
other info:
http://www.wakeboardingmag.com/VTD/2008/Malibu/index.html?manufacture=1&boat=2