Allegiant Air Offers $40.68 Round-Trip Fare Between Long Beach and Sin City--with a Catch

​Allegiant Air is offering a screaming deal to promote the budget airline's upcoming new flight service between Long Beach and Las Vegas: a $40.68 round-trip ticket.

Certain restrictions apply, and if you bring any luggage other than a carry-on, you'll be charged $35 per bag.

Oh, and there are a couple other huge catches.

VisitLasVegas.com

​The Long Beach to Sin City flights do not begin until Dec. 15, you have to make your reservation by this Saturday to snag the cheap fare and you have to fly out by Feb. 11, 2011--although the offer is invalid Dec. 30-Jan. 2. The trips are offered Sundays, Mondays, Thursdays and Fridays.

But here is the biggest bugaboo: you have to buy the ticket at the Long Beach Airport counter (or LAX if you want to fly out of there instead) to get the $40.68 deal. If you book the flight online, a $14.99 per passenger "convenience fee" is added. (How convenient--NOT!) And that fee shoots up to $44.97 per ticket if you make the reservation by phone.

The fine print on allegiantair.com also states the offer is "based on a buy one (1) air/hotel package." But Allegiant's vice president of marketing and sales Tyri Squyres told the Los Angeles Times the hotel-package stipulation has been waived for this particular promotional offer.

You can call Allegiant at 702.505.8888 for more information but, remember, you'll get dinged for more fees if you book by phone.