One of the things many people can expect when they take their vacations is a pitch to buy a time share.

A time share is a way for regular working folks to have a piece of a vacation home, albeit one week at a time.

U.S. time-share sales continue to climb. In 2004, sales grew 21.4 percent over the year before, to $7.87 billion, according to the American Resort Development Association, a Washington-based trade association representing the vacation ownership and resort development industries. About 1,600 U.S. time-share resorts serve 3.87 million households, according to the association.

In 2004, a two-bedroom unit sold at an average price of $16,977. Studio/hotel units sold at an average price of $6,262. One-bedroom units sold for $10,821, while three-bedroom and larger units sold for an average of $24,166.

I know how many people get persuaded that a time share is right for them. A salesperson shows them around a resort where children are laughing and splashing in beautifully maintained pools. The adults are sipping chilled drinks with little umbrellas in them.

They get shown units with spacious living quarters. They like the idea of being able to exchange their week for a stay at other wonderful places around the country or world. They want a piece of this life.

And before they realize it, they've signed a contract to buy a time share.

But before you buy into this vacation dream, ask yourself if this is something you can afford. In the interest of full and fair disclosure, I own three time-share weeks. I've enjoyed the ownership and ability to stay in five-star vacation resorts for several years now.

But I didn't buy because it was an investment. Time shares are basically future vacations that you're buying today. In fact, don't even think of this purchase as an investment. And if the salesperson says it is, get up and walk out.

For years, the time-share market suffered from shady and illegal sales practices and poorly run developments. However, with the entry into the market of such major chains as Marriott, Sheraton, Hilton and Starwood, the industry's image and resorts have improved. Still, the resale market is dicey. You don't always net a profit when you sell a time share. Often, sellers are lucky to get back what they paid for it.

So, before buying a time share, consider these tips from the American Resort Development Association:

* Visit before you buy. Talk to existing owners about their ownership experience. Many time-share resorts offer discounted mini-vacations (sales presentation included) that will give you a chance to check out the place. If you don't want to go through the sales pitch, just rent a time share to check it out without any sales pressure.

* Check out the developer. Call your local Better Business Bureau or check with state consumer authorities to see if any complaints have been lodged against the time-share company.

* Read all documents carefully. Because there are so many options for time-share ownership, be sure you understand exactly what you are buying.

* Make sure you understand the rules and restrictions for exchanging your week for other locations. Call the time-share vacation exchange company to find out if the time-share resort you are considering is in high demand. If so, you have a better chance of getting an exchange week you want because other vacationers want to stay at your home resort.

* Take a timeout before you buy. Study the paperwork outside of the sales presentation. You may even want to wait until after your visit so you won't be tempted by that sun-drenched beach.

If, after you've taken all these precautions, you think a time share is right for you, here are some ownership options, according to the Federal Trade Commission:

* Deeded Time Share. Your interest in the time share is legally considered real property. Much like a house, it's yours to sell, use or give away during your allotted periods. You and the other time-share owners own the resort. In this case, you will likely have an annual maintenance fee. The average maintenance fee in the United States is $479 per week of annual use, according to the resort association. For many top-notch resorts the fees can be more than $1,000 a year.

* Interval Option. This is where a developer owns the resort, which is made up of condominiums or units. You buy the right to use a week for a specific number of years -- typically between 10 and 50 years. As with a deeded time share, your interest in the resort is still considered your property.

* Fixed or Floating Time. In a fixed-time option, you buy the unit for use during a specific week of the year. In a floating-time option, you use the unit within a certain season of the year.

A time share can be a great way to travel and see the world. But make no mistake about it -- this purchase is a luxury. Don't even think about buying a time share if you don't have your financial life together. If you don't have at least three to six months of living expenses saved up, you have no business buying a time share.

If you are struggling to pay off credit cards, you can't afford a time share.

If you are not properly saving for your retirement, don't even go to a time-share sales presentation.

Michelle Singletary discusses personal finance Tuesdays on NPR's "Day to Day" program and online at www.npr.org. Readers can write to her at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Send e-mail to singletarym@washpost.com. Comments and questions are welcome, but due to the volume of mail, personal responses may not be possible. Please also note that comments or questions may be used in a future column, with the writer's name, unless a specific request to do otherwise is indicated.