This article outlines several tips in buying: http://www.bankrate.com/natl/news/real-estate/20070410_timeshare_vacation_pressure_a1.asp
Briefly, the 7 tips are:
- Know the numbers
- Deal with high pressure sales tactics
- Walk away
- Don't buy into the "real estate" spiel
- Ask a lot of questions
- Pick a vacation spot because you like it
- Become a second owner to avoid depreciation
Many people find joy in vacationing in a certain location and a time share fits their goals. However, time shares don't necessarily increase in value so know your product before you buy.