The first thing you should ask a general contractor for is their Florida License Number. If they can only provide excuses, run. It should be on their advertising, business cards, etc.
I know about Dalton Place. Before you build, make sure how strict the architectural review committee is for that subdivision now. That could cost you money. Also most of that subdivision is not in an X flood zone -- it's in a VE. That will make your insurance higher -- if you can get it. Sometimes parcels with an X rating have to do some major shopping for insurance. Check out http://portal.nwfwmdfloodmaps.com/ and you can navigate to your parcel to see your flood zone rating.
There's more to building than price per square foot. And BTW construction costs have gone up since a couple of years ago.
Generally, Cost of construction plays an important part to develop the property. Before you start construction,Once contact your local builder and verify the price estimation. Within your budget, You can get the best home according to your ideas.
It all depends on your design and finishes. You should still be able to build for that price if you work with a budget conscious architect, good builder, and are conservative with interior design.
Thank you all for your comments. We have looked into the cost of insurance (we are in Dalton Cottages in zone X) as well as taxes. We are well aware of the architectural/structural requirements after going back and forth with our architect's plans and the HOA but it will all work out. We plan to get several bids when we get a little closer - just trying a get an idea of average costs right now for a new house in seagrove. A friend just met with a builder there a couple of weeks and it looks like she may be able to build her (similar) house for $150/ square foot. Thanks again everybody.