I might have to disagree here. I just completed an assignment in a 54 home community with very few sales. Most sales were larger than the subject. There was 1 pending sale that is scheduled to close within 3 days. Realtor provided all information including concessions, so I used that as a sale and included comments as to why. This property was similar to the subject in size and in small areas, in my opinion should be utilized.
You cannot use it as a sale comp if it has not closed. What if the house burned down in those 3 days or if the buyer died? Report it as a pending sale.....or, wait the 3 days until it closes and ask the title company to provide the document number.