It depends....
Read the REO form, it asks for a quick sale value (90 ~ 120 days).
So much depends on your local market, that is why the bank, agency, or Fannie Mae relies on a local appraisal as well as their managment company.
I always try to use REO sales for comps, if I can find them, for the "as is" value. Once the property is brought to average market condition I prefer to use normal sale transactions. Often an REO that has been refurbished and updated will bring more than a typical "average condition" house because so many things are new, ie, appliances, paint, carpeting.
The Fannie Mae property manager here likes to find out my value conclusion before putting the property on the market, he then tries to get them to list it about 10% below my number for a quick sale. If it is a manufactured house he tries to go even lower. We have seen a bit of "dumping" of REOs recently which, in my opinion, isn't really necessary.