Try Travelocity. Flights from $371 rt. We have always flown Continental Lax-Houston-Coz. This year we flew Mexicana and will always use them....LAX - Mexico City-Coz. Very spacious seating and you actually got a meal and free drinks if you want. We had to take the red eye (12:15), but arrive in Coz around 10:00 am. The connections were much easier. Customs was a breeze. No standing in line on arrival and when we left we didn't have the search your bag scenario...Just went to the ticket counter and checked in When we arrived at LAX, Customs again was fabulous... Checked our passport and off we went...no search.
In previous years, going thru Houston we were always running to make the connection and having to go thru customs and collect your bags was a nightmare.
Try going thru Island Dreams or another broker. They always have specials.
We have stayed at Fiesta Americana the last 4 years and tried the All Inc.for the first time. It was perfect! Included drinks. We ate breakfast and lunch there and went into town 6 times for dinner and it was still less expensive than previous trips. We ate dinner at the hotel 6 times. They tell you can only eat in the upscale restaurant 2x, but just get to know Luis and you can eat there as often as you want. The buffets were typical.....sometimes good, often average.
Fajitas at poolside were great.
Good luck