well you can use the property appraisers website to get an idea....just take the address of the house you are looking at on a realtors website and plug it into the appraisers website and see what they paid. It is also a good tool to see the actual assessed value of the property, what the current owners paid for the home, a REAL square footage (realtor.com is a little exaggerated)...that kind of info. Also you will be able to check if they owners did any additions they are not advertising (ie. converted a garage to make a 3 bedroom home a 5 bedroom home)
here's the site, ps. it gets addicting so take it slow -
Property Appraiser - St.Lucie County, FL, go to real estate tab, then search by address.
Happy searching!
Oh you can also look on the property appraiser website to see how the tax is calced. Keep in mind too, FL has a 50,000 homestead exemption which helps lower the taxes significantly.
If you buy a 100K home, you will only be taxed on 50K. If I remember correctly, we paid less than $1000 a year when our home was assessed at that price. I could be wrong though, it was several years back, they might have changed the formula.