Unless Lime prices have changed since Marko bought his in July, the phone, sim and tax were just under $20 US. Less than half the price of Digicel. It is more expensive to call a digicel phone (than another lime, or even Canada or US, if memory serves me correctly) but their prices are lower than digicel... So you're not paying more using Lime, it may end up being less (been a while since I looked at a comparison of prices per minute). Correct me if things have changed.

I would never use my home cell phone for calls or texts while there. I do keep it in airplane mode with data off and use at my hotel for emailing/surfing via free wifi, then lock it up between use.