Is it expensive to live here?

I would say no. You don't have the heating costs in the winter as in northern states. However, you may make up for that in the summer if you're the type that over heats easily and needs frosty a/c temperatures. They don't tax food in Florida, there is no state tax and housing is much less expensive than you'll find in other states. Some areas can be painful on property taxes, but Florida also provides a homestead exemption that lowers taxes on a primary residence.