Puerto Rico is not a bargain budget Caribbean destination. There are no charter flights, few - if any - packaged tours, hotels are pretty expensive, especially in the winter season, though there are bargains. I payed $220 a night (with all taxes, etc, quoted rate was $170) at a venarable El Convento in the heart of Old San Juan. If you want to spend more time on the island you can rent everything from a small casita in the mountains (I had one for $200 a month, and that included a guy with a machete who came once a month to cut the grass around it and down the road to the nearest dwelling) to a beachfront condo in a resort with a lot of amenities. They run into thousands of dollars a month in touristy places. My large two-bedroom apartment in Aguada in a villa on a surfing beach (rocky,lots of coral, dangerous for children and novice surfers) did cost me $600 with electricity, water and high speed internet connection. For a smaller condo in a resort of Joyuda in Cabo Rojo (the driest part of PR, its Tuscany, thus popular with sanjuaneros during the summer) I will pay $700 in basic rent, $100 in maintenance fees + electricity (average of around $80 a month, depending how much I use ac), water (average of $40 a month) and a cable TV with internet ( a minimum of $56, but with digital TV and premium channels it will be closer to $100 a month).
Health is a real bargain - PR is not as bad as USA. I had to go to an emergency room once and for all tests, a drop ( I was severely dehydrated), medications, other meds, bed for half a day and two doctor visists - the diagnose one and a follow up before release - I paid $95 without insurance. Total. Besides, everybody who resides in PR for over a year has a right to a local insurance, but I don't know how much it costs.
Public transportation is a sorry capitel: there is practically NONE on the island, so everybody needs a car. And you can buy one used from around $1000 and up. Gas costs nowadays about $.92 to $.95 a LITER (for a gallon price multiply by 3.8). Roads, except of major (toll) highways are pretty bad, though not as bad as in continental Central America.
Food: you can eat cheap from road stands - many have tasty fare, snacks, lots of very inexpensive fruit. But if you like fresh vegetables, especially greens, beware, there is almost no variety and waht is is couple of times more expensive than in the USA. Bell pepper ca $4.70 a pound! I am not kidding! On the West Coast the best bargains are beach bars. Their portions are for young, hungry surfers with limited funds. Humongous appetizers (which for me are more than a meal) and main dishes will run you $ 10-15. Bear $1 for a local Medalla at neighborhood pubs, $4 at a pool bar in a posh resort.