You can use it as a supplemental comp (comp 4, 5, 6 etc...)
If the previous sale was an "arms length" transaction, then why on earth would you not use it? It is the best comp you will find because it is EXCACTLY like the subject.
Now, I would be hesitant to use the subject if the prior sale is signficantly higher than what the remaining subdivision is selling for, or if it appears there may have been other motivations behind the sale. I would also hesitate to use the prior sale if it is simply to justify a value that is higher than the rest of the market supports.
I just performed a review on a property, where it had previously sold for $3.6M 6 months ago, then foreclosed in March for $2.5M, and is under contract for $1.8M. The appraiser referenced the original sale of $3.6M to justify a current appraised value of $3.6M. What they failed to mention is: A) The prior six months ago was never in FMLS or GAMLS B) There are SEVERAL foreclosures on the SAME STREET. Market data was suggesting that there was some "hanky panky" going on. The appraiser also failed to think about the concept of substitution. There were SEVERAl active listings in the mid $1.5M's avaialble for purchase. Why would a buyer pay $2M more for a similar home?
As far as making comments, all you need to state is that you used the subject as additional support of current market trends, and that your appraised value is not based solely on the subject, but by the subject's market and competing properties.
FNMA Selling Guide, paragraph 406.02:The appraiser may use the subject property as a fourth comparable sale or as supporting data if the property previously was sold (and closed or settled). If the appraiser believes that it is appropriate, he or she also may use contract offerings and current listings as supporting data.John
