Dana nailed this question, Realty Trac value guestimates have very little correlation to market value. Presumably they are a big advertiser and source of revenue for Trulia, as these Realty Trac valuations create a significant amount of confusion for consumers using this site.
You are welcome to look for Cape Coral vacant land on our site, the prices are set in the MLS system. If you need some assistance narrowing the field, please drop us an e-mail
Good luck and happy new year,