I'd suggest Clive's transportation. They give you a free Red Stripe at airport
and will stop frequently along the way to let you replentish at places that
sell at local prices. Their rate is cheaper than what was posted, but I
don't want to specify. Cheapist beer I found in Negril is at the oriental
store across from Scotia Bank. Ask for cardboard cases as they are cheapest. My experience is that 2400 JA is about as cheap as you can find.

R. S. Bill