Lent in 2012 will start on Wednesday, the 22nd of February so Carnival is the week prior like Mardi Gras: Wednesday, February 15, 2012 - Wednesday, February 22, 2012. See...
Cozumel Insider - Cozumel Carnaval - Calendar, Schedule of Events & Information - Cozumelinsider
Cozumel Carnival 2012, Program, pictures, and discription.
and
Cozumel Mexico Travel - Cozumel Carnival
Booking well in advance will probably save you more than a discount code. Kayak.com and Matrix.itasoftware.com both show the cheapest flights to be going on the 14th and returning on the 21st or 22: $497 each inclusive on Continental. Or you could fly 15-22 San Antonio to Cancun for $395 on AeroMexico, and there is a wide choice on flight times - but I wouldn't.
You didn't answer but I presume there are two of you? For comparison, you could get the same Continental ticket and 8 nights at Suites Colonial for $689 including taxes, or upgrade to a suite for $5/night each. When I try Kayak and Orbitz for those flights and Villablanca, I get an error - so you may want to phone them. I have found the phone agents to be very nice and helpful.
I also see Funjet has a package, using Continental flights I think, with 8 nights at Villablanca for $806 each, plus optional upgrade to Superior room for $110 each. Their Superior rooms are upstairs but very nice, twice as large - like a Junior Suite. I suggest the upgrade! But you can do the flights for $497 and the room separately for $280 each or $374 for the Superior - so no savings there huh?
BTW, be sure to not book ground transfers or trip insurance thru a ticketing vendor. You can get the ground transportation for half as much there, and do much better on trip insurance.
Now, Cheapcaribbean.com can be difficult to work with online, but again - the phone agents are nice. I guess it tends to work that way more with sales than with support. :laughing:
I hope that gets you started ok...