First of all assessed values have NOTHING to do with what the house should sell for. It could be a benchmark to go by, but it has nothing to do with it's sale value. Here, in NC, the assessed values change between 4-8 years and remain the same for years. I am not sure what Florida does, but home sale prices can be over, at or under the assessed value which is set to tax similar homes similarly to each other. They do not take into account what is in the house at all so two could be next to each other and assessed the same while one is gutted out and the other upgraded to the max. You need to find a Realtor who can show you what comparable homes have sold for and base you offer on that, not a tax assessment.