I don't think you will find much under $500 that will do true wide angle pictures.
I am also a Realtor, and use one of these
for back yards and front elevations, and one of these
for interior work where there isn't typically so much light available. As you can see, it gets pretty pricey - that is just for lenses!
For $500 or under, I like the Canon point and shoot options. Something like this model
will take nicer pictures than the tiny ones - definitely enough for a feature sheet or website.