I am a little confused..
You say the homes are in the millions & you want to target homeowners that have lived there for a while & cannot afford the taxes. How do you propose to help them? Obviously they are not going to sell & move to another house in the area. Are these homeowners thinking of moving elsewhere where property is more affordable? So you want to list their house when they decide to move?
Where can they go in S FL that is more affordable

Are these retirees that may want adult communities? Then you would need to position yourself as an expert in retirement communities
Feel free to send them to Jacksonville!!

But seriously, I do get a lot of referrals from other Sellstate franchises in S FL whose customers cannot afford to live there anymore.