I'm going from San Pedro to Chetumal on the water jet next Tuesday. Then I have an ADO bus ticket to Cancan. I will have overnight in order to catch a 7 AM flight.
I do not speak English and would like to find a very inexpensive place at or near the airport with shuttle service.

I'm looking for advice.

what language do you speak?

I'm tempted to be a smart a$$ but the truth is I do not speak Spanish; and sometimes I have trouble with English.

You won't have a problem finding a hotel - the cabbies and hoteliers speak English in Cancun.

The bus makes a few snack stops along the way, that is the only time you might wish you spoke a little Spanish so you can get a snack. But living here you will be familiar with the food and their names.

The trip is nowhere near as daunting as you may fear.

Be aware - the airport is NOT in Cancun - it is a ways out of town. I don't know the best place to stay and I don't know about budgets etc. I haven't stayed in Cancun since the early 1990's.

You're best staying in Playa del Carmen and then going to the airport from there. It's a shorter bus journey, both from Chetumal and to the airport. There is a couple of hotels I've used there. I'll PM you.

If you don't mind night buses, there are a couple of express buses that depart from Chetumal (at 10 pm and 12:30 am) and go direct to the airport. It's a 5.5 hour trip so the 10pm bus will get you there with plenty of time to spare. The 12:30 am bus will get you there at 6am (probably too close for comfort).

I usually stay in Playa, but with a 7am departure time, I might not advise this for you because Playa is about 1 hour south of the airport and the airport express buses (110 pesos) start running at 5am (getting you to the airport at 6am). You would have to leave Playa by 3 or 4am. There are probably other ways to get to the airport but I don't have any details about them. If you were forced to take a taxi, it would be more expensive from Playa than Cancun city.

Cancun City is just under 30 minutes north of the airport, and there are frequent buses to the airport. There are a few hotels near the bus terminal -- Hotel Alux (I think it's a lower budget hotel) gets good comments on forums (I've never stayed there).

Hotel Alux is nice [only stayed at the one in Playa though not Cancun] http://hotelalux.com/

The Marriott Courtyard has a free shuttle to the airport and is the nicest and closet hotel to Cancun Airport at this time.

http://www.marriott.com/hotels/travel/cuncy-courtyard-cancun/

Mr. B
That is just the kind of info I was looking for 10 PM bus.
Is that an ADO bus? I already have a ticket with them. Would my ticket to Cancun let me get off at the airport?
I have a contact in Chetumal so that I could spend the day there and then sleep on the bus.
Otherwise it looks like the Comfort Inn would be my next best bet.

I'm glad to see this thread, I'm taking the same trip then jumping off to cuba.