Is That $19 Deal for Real? Yes, Sometimes

— -- A couple of weeks ago, I wrote about people who think they're too broke to fly and how they may be dead wrong; I then cited some truly super airfare deals, including tickets for $19 one-way.

Then I heard from nay-sayers. "Yeah, they may advertise flights for $19 but that's just one-way," said a frustrated shopper after encountering a lopsided deal. "The return trip might be ten times as much." This may be true in some instances but I assure you it's not the case every time.

Here are 5 things to know to get those super airfare deals.

1. Advertised fares are often one-way prices.

In many cases, prices shown on U.S. airline website ads are one-way fares. If that's the case, and you plan to return home, naturally you'll pay more than the one-way fare. The question is, will the round-trip ticket be precisely double the one-way fare? Sometimes yes, sometimes no.

2. Some bargain fares are the same price in each direction, some aren't.

These airfares were offered by a discount airline earlier this month and prove that sometimes super-deals really do exist.

• Atlanta to Boston: Advertised price, $19 one-way. Round-trip price, double ($38)• San Antonio to Atlanta: Advertised price, $59 one-way. Round-trip price, double ($118)

On the other hand, some deals do differ in price each way. More recent examples.

• Denver to Cancun: Advertised price, $59 one-way; return price, $73 • New York to Stockholm: Advertised price, $182 one-way; return price, $176

Wait! Look at that second one again. The return price ($172) is actually cheaper than the advertised deal ($182). But don't expect to see this very often.

3. Flexibility may be required

Airline sales usually include a lot of fine print; read it all. Generally airlines limit super-deals to the least popular times to travel including off-peak months (the NY-Stockholm deal was for a flight in February). Or super-deals are limited to unpopular flying days like Tuesday or Wednesday. Some airlines may also offer these deals on widely spaced "select days," which means you might find your bargain departure flight in January but no same-priced return flight until March.

4. Don’t sweat a few dollars

Did you find a good deal in one direction but a higher fare for the return flight? If it's just a few bucks, don't sweat it. For example, had the Denver/Cancun fare above been $59 in each direction, it would have cost $118 -- which is a super deal. But the actual price of the round-trip flight ($132) is only another $24. That's still a good deal.

5. There will be fees

Discount airlines make a lot of money off a wide variety of fees including things we're not used to paying for like non-alcoholic drinks and carry-on bags, or even seat selection. It's a big reason why they can offer such low prices.

My advice is to avoid as many fees as possible: Pack a bag that fits under the seat which is usually free; fill up an empty water bottle after the security checkpoint and bring a lunch from home. If you don't care where you sit, play seat roulette and let the airline choose for you. It'll probably be a middle seat, but it will be free.

The opinions expressed in this article are those of Rick Seaney and do not reflect those of ABC News.