Tell people you're thinking of buying a time share and you'll find that there are a lot of opinions out there.

"I wouldn't advise buying a time share if my life depended on it," says Chuck Whitlock, author of "Scam School" and "Easy Money." Whitlock says time shares are good properties, but the business practices behind selling them borderline legitimacy.

On the other hand.

"In all my years of working in this industry, I've never heard anybody say they were not satisfied with the product -- new or used," says Howard Nusbaum, president and chief executive officer of American Resort Development Association, or ARDA, the trade organization for the time share industry. "There's about a 90 percent satisfaction rate from the people who own the product."

Despite the debate, the time share industry is booming. According to ARDA, sales reached $8.6 billion in 2005, and 4.1 million households owned one or more U.S. time shares.

Buying a time share If you do decide to buy a time share, you should do your research before agreeing to anything. Here are seven things you should know before you start shopping.

Be an informed shopper 1. Know the numbers. 2. Deal with high-pressure sales tactics. 3. Walk away. 4. Don't buy into the "real estate" spiel. 5. Ask a lot of questions. 6. Pick a vacation spot because you like it. 7. Become the second owner.

1. Know the numbers. Before you buy, know how the property owners make their money. The average time share purchase is roughly $16,000 for about 20 years of use. The nicer units are in the upper-$20,000 to mid-$30,000 range. There's also an average yearly maintenance fee that can run anywhere from $300 to $500. 

"Seems very little to spend," says Martin Weil, founder of MW Investment Strategy Group. "But a condo unit that might sell for $300,000 is being sold instead for $20,000 times 52 (weeks). Maintenance fees of $500 a month are now $500 a week (for the developer)."

According to the Federal Trade Commission, or FTC, maintenance fees can rise at rates that equal or exceed inflation. Owners must pay these fees and taxes, regardless of whether they use the unit.

Weil says the time share economics put an enormous profit into someone's hands at "the expense of the buyers."

2. Deal with high-pressure sales tactics. Time share salesmen have earned a dubious reputation. It's become standard practice for them to dangle freebies in front of you so you'll agree to spend two hours learning about your "dream vacation."

Lisa Ann Schreier, author of "Timeshare Vacations for Dummies" and a former time share saleswoman, says the freebies are part of their shtick to pressure you into buying.