My son and his GF will be in SMA during our next trip to Isla Mujeres in September. What is the best, most economical way to get them up to Cancun? I see flights from the area are pretty expensive ($400+ each, round trip) but flights from Mexico City are half that. The ADO bus is 23 hours from Mexico City alone, so that won't work.
My initial thought is they should take a bus to the Mexico City airport and fly from there, or even work in a few days in Mexico City while en route. Any advice?