Note that initial buy in is only part of the costs.
You'll have $4-5 per point in fees every year on each point, and those are subject to inflation. On a 60 point contract its about $270 a year or something, depending on resort.
Also, DVC only gets you the room (but no room tax!), you still need to get to WDW, buy park tickets, eat, get yourself some Mickey Ears, etc.