You already know that if something looks too good to be true, it probably is. But clever scammers also know that you have an “override” button. Like invoking a well-known travel brand. Or using the name of a trusted media outlet.

Margie Swenson says she fell for such a ploy perpetrated by an Orlando-based company called Travelcomm Industries, which operates under the name Patriot Travel, Cheap Tickets Cancun, Cancun Adventures and, until recently, Priceline Cancun.

Here’s what happened:

Last August, we decided to plan a Cancun vacation for April. I had received a copy of a clipped article from USA Today dated August 7, 2007. It came from the “Money” section. Someone had handwritten two notes on it and drew arrows to the area of the article the note applied to. The two notes read: “I know you are going on a trip this year, thought you’d be interested.” and “Call … and ask about Cancun 6 day all-inclusive for $300/person.”

Swenson phoned the company and was told the rate included food, drinks, room service, and even wind surfing. A representative assured her that she could choose from 16 hotels which were listed on a Web site called Pricelinecancun. Swenson and five other friends booked their flights to Mexico and paid for their hotels but were not given confirmations.

In October, I called the company to choose our hotel. An agent informed me we would be in Cancun during peak season and that it would cost us an additional $200 per room. I agreed to pay. Then I was told that there were only two hotels to choose from. Both of them were three-star hotels — the Maya Caribe and the other the Dos Playas.

I selected the Maya Caribe after one of the agents convinced me it was really nice.

But when she checked into the Maya Caribe, she says she realized she’d been duped.

The lobby looked like an old gas station from the 60’s that was emptied out and a few chairs put in there. I knew we were in trouble at that point.

Our rooms were not ready for occupation yet, so we headed over to take advantage of our “all-inclusive” meals. I spent 20 years in the army and never ate in a mess hall that bad.

We looked at the Dos Playas hotel and it looked like old barracks. We knew the Maya Caribe had to be better. No it wasn’t! We walked for quite a distance to get to our rooms. They didn’t qualify for rent-by-the-hour rooms. There are no hotels in the U.S. that I can compare this place to.

After one night in these substandard accommodations, Swenson and her friends found another hotel that was up to their standards. When she returned to the States, she contacted Travelcomm to ask for a refund. “I was flat-out told I wouldn’t get a refund,” she told me. “I asked for a name and address of whom I would contact and was given something but was told I’d be wasting my time.”

So what’s going on here? I asked Priceline about this apparent scam. Here’s what a representative told me:

In the late summer/fall of last year, after learning about them, we filed complaints with the Florida Attorney General and the Florida Department of Agriculture and Consumer Services. You won’t see that URL anymore, since we also successfully stopped their further use of it.

A USA Today source says the newspaper is aware of the scam, too, and that its attorneys have been “trying to shut it down.” Periodically, the newspaper is contacted by travelers who have fallen for the Cancun fax offer. Obviously, the article that’s being faxed around is a fake. “It annoys me that they’re using USA Today as the bait,” I was told.

Can Travelcomm be stopped? A lot of folks have tried, from former employees to the federal government.

It’s likelier that people will just stop falling for the scam, forcing Travelcomm to go legit — or go out of business.

In the meantime, here are a few tips worth repeating. If it looks too good to be true, it really is. I mean, come on. Six days of an all-inclusive resort for $300? You’ve gotta be kidding me.

A faxed offer? What is this, the 80s?

As for invoking the names of a well-known travel brand or a trusted media outlet, I think maybe the X-Files rule applies to this situation. Trust no one.