Despite what the Rev says we have been back to Mexico many times after visiting Negril.
It is easy to do the same thing in Negril that you do in Mexico as far as finding a reasonably priced hotel and buying food on your own. Decent hotels can be found cliff side in the $50 to $75 range which would be a similar price of a hotel on Isla Mujeres or Puerto Morelos. Local Negril restaurants sell very good meals in the $5 to $15 range, again prices similar to what you might pay in Play del Carmen or Merida.
We can do 2 weeks in Negril for about the same price as a Yucatan vacation. If we stay on Negril beach, it is slightly more expensive than Mexico, but not double the price. We don't do AI in either place.
Negril does have a good vibe, but can be intimidating to those not used to the beach higglers, something you seldom see in Mexico. Negril has a nice music scene, Mexico has some fantastic ruins and culture. Communication is easier in Jamaica as they speak English and tap water is good to drink. Sunsets way better in Negil.
Both places have good air service at similar prices from Philly.
the only difference is that we normally book our hotels in Negril in advance but never do when going to Mexico.
Regards,
Bob