There’s no tax on buying property, however, property taxes are a percentage of your property’s assessed value. In my locality, the assessed value has a lot of deductions whereby my 400K house is only taxable as 32K in value, so I pay 3K/year in taxes.

I can’t speak for Florida, but if it’s like Arizona, their property is worth a lot more than 4M if their total tax burden is 90K/year.