As an economist with a Washington tax consulting firm, Nina Atkin knows numbers. To her, the $1,600 discount certificate she got in the mail for a "fabulous dream vacation" valued at twice that amount seemed like a lot of fun and adventure for the money.

The vacation offer certificate, in the form of a "check," promised three nights at a plush resort in Fort Lauderdale, Fla., a two-day Caribbean cruise, a free rental car and complimentary tickets to Disney World during two nights in Orlando. "The letter said I was offered this because of my responsible financial history," Atkin says. "If I booked within 48 hours, I'd receive two future bonus trips."

Instead she got headaches—big ones. After paying a deposit of $898—and extra for a beachfront room—Atkin learned from other "winners" of the same offer that the Ramada Plaza Resorts hotel was actually a one-star facility 15 miles from the beach. "The tickets to Disney World are contingent on sitting through an all-afternoon time-share presentation, which they don't mention," she says. "I heard from some people that the 'free' rental car cost $400 in taxes and fees. And the cruise is just horrible, with lots of tack-on charges."

When Atkin tried to cancel the next day, she says she was told her trip was nonrefundable—even though Florida law allows 30 days to cancel and get a full refund for a vacation in that state. She got her money back after spending days writing authorities to point out laws the travel provider broke.

Americans lose more than $12 billion a year on travel scams. Bait-and-switch certificates like Atkin's generated about half of all travel-related complaints filed with the Central Florida Better Business Bureau in Orlando, says Judy Pepper, the group's president. Usually, she says, sleazy marketers make their pitch via unsolicited telephone calls, faxes and mailings; more recently, they're using Internet pop-up advertisements.

"They make you believe you're getting a wholesale-priced vacation," Pepper says, "but usually you wind up with less-than-desirable accommodations." There may be hidden restrictions such as blackout dates at resorts and fees on certain travel dates. "You end up paying more than you would making your own arrangements," she says, "and receiving less."

Ramada Plaza Resorts, with locations in Orlando and Fort Lauderdale, has generated thousands of complaints for its bait-and-switch tactics. Company president Daniel Lambert and other officials declined comment to Scam Alert. Ramada Worldwide Inc. says the hotels are franchises that are independently owned and operated. While Ramada Worldwide is aware of the complaints, says spokesperson Christine Da Silva, it is not responsible for or involved in vacation packages offered by hotel owners.

Some tips for staying off Rip-off Road:

* Don't be tricked into a "buy now" offer or provide credit card or bank account numbers until you have travel details and restrictions in writing.

* Don't respond to call-in offers with a 900 area code, or you'll pay exorbitant phone rates. Beware, too, of area codes 876, 868, 809, 758, 784, 664, 473, 441 and 246; they're in Caribbean countries and can charge high rates.

* Be skeptical of offers with buzzwords like "vacation offer," "you're eligible to win," "guaranteed" or "free."

* Avoid booking travel accommodations more than one year in advance. One common ploy — particularly for phony cruises — is to "reschedule" shortly before departure and assign a new date that may not fit into travelers' schedules.

* Check travel companies (and file any complaints) with the Better Business Bureau and the attorney general's office in your state and the company's home state.

Sid Kirchheimer is the author of AARP/Sterling's Scam-Proof Your Life.