I disagree. Using this scenario, there are still 25% of sales that are non-distressed in nature which should be considered and perhaps be the only comparables included within the report. An analysis still has to be performed to determine whether REO and short sales are selling for the same amount or less than non-distressed sales, all things else being considered equal. It is up to the appraiser to explain why distressed sales were utilized in lieu of non-distressed sales and up to the appraiser to explain the necessity for making, or not making an adjustment to them, based solely on any differences in sales price between these 2 types of transactions (or perhaps 3 as one could make the argument that short sales have a different stigma associated with them than REO's).
You appraise within the same markets I do and the worst markets are at about the 75% to 80% number of short and bank owned sales and current listings. And in every instance, where the gap may not be as substantial as those markets were the percentages are around the 25% to 35%, I have found these properties almost always sell for less than non-distressed sales within that market area. There may be a handful of exceptions from time to time but the analysis must be performed. I just did one where I had 3 sales which were non-distressed and 9 sales which were. And these 3 sales sold higher than any of the other sales, both on a sales price basis and a price per square foot basis. So I could either use those 3 sales only, or if I utilized any of those distressed sales, an adjustment had to made.
Guess which choice I made and what explanation I provided within the report substantiating why I did what I did. If the market was different and there was either no non-distressed comparable sales within the market area or there is little to no difference in the market value between the two, the approach of course would be different but in order to make such a statement, there has to be the supporting analysis substantiating any statements, lack of adjustments or adjustments you make.