Very difficult to give accurate figures as there are so many variables - Size of villa, management company charges, insurance, utilities (will you have reclaimed water for the garden ?), type and age of pool heating and A/C, how much maintenance you do yourself (painting, general repairs etc), type of internet, TV package, phone package etc etc and don't forget the local taxes (12% in Polk) on everything you earn. Hotel licence. Pest control. Regular replacement of fixtures and fittings, advertising costs and the list goes on.
Our villa is occupied in to the 30s weeks a year but that includes 6 to 9 weeks for us (usually in low season).
Overall I would say we brake even and have two or three cheap (only pay for flights) holidays a year but I think very few owners would make a profit after all costs and maintenance are taken into account and that is without charging for the hours you will spend responding to enquiries and dealing with guests. It also depends if you need a mortgage of course.

We bought when the exchange rate was around $1.75 to the £. It is now in the low $1.20s and so if we sold now, even with the drop in villa prices since 2005, when we bring the money back to the UK we will have a profit, but you can not rely on that.
All in all, get a villa if you want to use it yourself and you enjoy the contact with renters and DIY, but don't do it just to make a profit - you will be disappointed

Sue