Keep in mind that square footage costs do vary, and doesn't account for exact location and other considerations, such as property size, condition, etc.; therefore, it's really in your best interest to also review comps, recently closed sold similar properties in the immediate area. Consider working with an agent of your own, he/she will be your best guide.
What are you looking for? are you trying to find out the price range of homes in that area or are you looking to buy. Talk to a Realtor. Perhaps the one below who has taken the time to respond to you. There are always so many variables and when talking to someone both of you can ask the questions to get you what you are really looking for.
east end homes are rarely on market and only one sold since aug 2011. That was a handyman special on n. yachtsman for $ 425k... so really not a measure of price value.
if it were on seagrape or buttonwood..get 700k and up for off water.
let me know if you need any more info.
what are you looking for?