Table of Cameras for Real Estate Photography

Cameras with at least 24mm wide-angle lens and External Flash Capable

From: Photography for Real Estate Marketing by Larry Lohrman

The CoolPix 995 and 4500 do not have a hot-shoe but have a Sync cord connection so that most external flash units can be used if a flash bracket is attached to the camera to mount the flash unit on.
The CoolPix 995 and 4500 are no longer made but are widely available via EBAY and other used camera sources.
Film SLR cameras are still very usable for interior photography and in most cases less expensive than digital, I included the Nikon 6006 because it is still widely available along with a range of wide-angle lenses on EBAY and other used camera sources.
For digital SLRs I recomment you take a look at Ken Rockwell's excellent review of "Digital Wide Zooms". There are a number of ultra wide zooms you can choose from and Ken's review will help you choose the one for your needs.
I don't have prices on this equipment because the prices change all the time. It's best to check prices at your favorite vendor or some site like www.pricegrabber.com for the latest prices.