Purchasing advice in future proposed higher flood plain

[Erik Guilfoyle]

I'm in the process of purchasing a home near the water in the North East. After having an elevation certificate done yesterday, I found out that this house is currently in a flood zone at a height of 6 feet and my base floor is 7 feet (acceptable). However, this 2006 height has a 2014 proposed change (preliminary adjustment to the height) of 8 feet (not a good thing). I'm told this change may take place tomorrow, next year, 10 years, it's unknown.

Prior to the elevation certificate, I've received some wildly different quotes for insurance. The worst was $5800 for flood only, the 2 best were $2600 and $1750 for liability including flood insurance (the last is apparently using satellite topography for creating rates).

My question is, what should I consider before deciding to make this purchase? What might I expect of my insurance if the map changes after my purchase? And, should that last super low quote for insurance concern me?