Run a search for accomodations to find out which hotels are the cheaper ones. You'll probably want to pick one closer to town. Our last time down, we stayed at Casa Del Mar. It was part of a package but you can contact the hotel their website for rates and for dealing directly with the hotel. It's not a great place but it ain't that bad either. I believe it's rates are decent. Papa Hogs is close to the hotel. They are an alright operation. Alot of people rave about them, but I wasn't as impressed with them as everyone else seems to have been. There boats show some wear and tear and the smaller boats can be a little tough getting back into. Also they didn't seem to be as organized as they could have been. Their DM's are really good though, and will give you a little freedom once they are comfortable with your skills.
If you go, you gotta hit Palancar Reef or Columbia Reef (deep, not the shallows), they absolutely ROCK!
Aren't you moving to Houston for a spell? If so, you'll have to hook up with the Southern Swampdivers while you're down there. Maybe we can plan a group dive at Lk. Travis in Austin one weekend.