I live in Key West where everything is high except for salaries. Some "studios" about the size of a hotel room rent for $800/month. A cottage (which is a small house in somebody else's back yard) can rent for $1500 - $1800. A 2 bedroom condo can run $1600 - $2200. Almost all landlords expect first and last month's rent plus a security deposit. Then come the utilities and the deposits for that.
Now that I've covered housing, gas is currently $3.70/gal on average. Want to go downtown? Expect to pay $10 to park in a lot or pay 25 cents for maybe 10 - 25 minutes for on the parking meters. Parking tickets are $35. Of course, you could risk your life riding a motor scooter or you could ride your bicycle and dodge careless drivers and getting your bike stolen on a daily basis.
Food is higher because this is an island. Eating at restaurants is high too, but we've all got to eat, right?
Like drunks and rude tourists? Go to Old Town. The sidewalks are crowded with them. They seem to leave their brains at home when they come here for vacation. Homeless people? We've got plenty of them too. Many live on the beach and are rude to people who want to go there to enjoy their day.
Other keys such as Big Pine are cheaper and quieter. It's also a 3 1/2 hour drive to Miami if there are no wrecks on US 1, the only road into the keys.
So why do we live here? The weather, the relaxed life style. The water. I live in Key West because I work here and drive a very old car. It wouldn't be cost effective or easy to get to work if it broke down and I lived up the keys some. The last time I took a cab to work, it cost $15 for a 3 mile ride.
Come to the keys for an extended visit and see which one you like the best. If I didn't live in Key West, I probably would live in Key Largo. There are plenty of other keys to chose from, but make sure you can easily get a job you enjoy with a salary you can live on.