My favorite place in the world but WAY out of my price range. Years ago (when it wasn't as pricey) we looked into it but I felt that with our children's activities (sports, dance, music, art classes for example) it would be a little too much driving 'over the bridge' on a daily basis. Not sure I was willing to sign up for that.
Would give my eye teeth to be able to live on Upper Captiva...it's just the most unbelieveable place but not really 'real life' with kids. You get there by boat and only golf carts are used on the island, no cars or trucks of any kind. Paradise.
Good luck in your quest. You are certainly barking up the right tree as far as I'm concerned.