— Stanton, via e-mail
I’ve done some research and bookit.com seems to be a good site with lots of information in addition to a booking engine. I’d give it a try and compare it to some of the other booking engines I like. I’m also a big fan of Kayak.com which is a meta-search engine comparing the best of a number of different booking engines.
Spirit is an ultra-low-cost (read no frills) airlines which I’ve flown. They serve a limited number of destinations, including many in and around the Caribbean (see image above).