There is a lot more to pricing than this. For starters, it is way more expensive to cover a huge land mass like the USA with cell towers, and those costs get passed on to consumers. To build out wireless towers on a small island is way less expensive, especially when you're not trying to cover everywhere and aren't terribly concerned with data speeds. Those basic phones you puchase in JA sure are cheap, they're also 15+ year old technology that is extremely cheap to manufacture.

The other main issue is that when you call from JA to the USA with your USA SIM card, you are using the Jamaican cell phone company to complete the call, and they will bill your carrier (Verizon, AT+T, etc) whatever they can get away with... and then your carrier passes those costs on to you.