From a marketing standpoint the simple answer from un-informed buyers is probably yes, but it is not a simple question. What you are saying is that your home was determined by recent studies to be within the flood plain. I wrote an article in Life on the Water here in the Tennessee Valley where I said:
Before you buy your dream lot (home) or acreage on the water, be sure to have a survey to locate the 100 year flood line also known as the boundary of the flood plain. The flood plain is divided into the flood fringe and the floodway. Generally speaking, you will be required to build your finish floor one foot above the 100 year flood elevation on any site in the flood fringe. Beware the floodway line! It is difficult if not impossible to get approval to build in the floodway unless it is at existing grade with no fill. For example, you could pave an area to park or store you boat or RV. Appreciate the flood way for what it is ...an area clear of buildings and other obstructions so that flood elevations will not be
increased significantly during a flood event. The flood way can be the most beautiful part of your site.
Just make sure you have enough area to build your dream home which is not in the flood way.
An existing home does not allow you to plan your finish floor elevation. You must work with the existing conditions. If your existing finish floor is below one foot above the 100 year flood elevation, you will have to pay flood insurance. The price varies ( I think) according to how much below the required building elevation you are. It could be relatively cheap or expensive. If you are lucky and the existing house is one foot above (check local regulations and you financing institution) the 100 year flood elevation, then you "may" not have to pay for insurance. Assuming your lot, or parts of, is in the flood plain, they will probably try to charge you for flood insurance. You may be able to avoid flood insurance if you will get a surveyor to certify the elevation of your finish floor (or bottom of wood where you have a crawl space) is one foot above the 100 year flood elevation and file for a Letter of Map Amendment (LOMA). As always check with your local officials, but being in the flood plain shouldn't be scary...just do your due diligence.