The biggest problem is the buyer’s perception. Most new buyers have probably heard too many horror stories on the news about forclosed/abandoned homes which leaves them with the perception that the home is either a big risk or not worth buying. Until the negative stories stop, the perception won’t change no matter what was done to the house.
(Maybe someone should contact Dan Ackroyd/ Bill Murray to make a Ghostbusters sign to show an abandoned house has been cleaned of all spirits )

The sale of a foreclosure, like any other property, depends upon the condition of the property. If a house is left vacant for a while and not taken care of by a property maintenance firm, it would be more difficult to sell, but no harder than if it were occupied by a homeowner that didn’t take care of their property and allowed walls, and roofs, and landscaping to deteriorate. In the state I live in, the cities and towns can charge fines on a daily basis to the owner of properties that are not being taken care of, including banks, in an effort to discourage letting a home sit vacant, effecting the property values of the other houses in the neighborhood.

I guess it will always depend on the buyer. But there is really something about foreclosed homes which pushes a buyer away.