Good morning! Yes, as someone stated below, the $20K difference really does have to factor in at what relation to the price of the home it is. $20K on $900K is nothing versus $20k on $90K!
Also, keep in mind some Realtors do factor in some "wiggle" room in their comps, though that varies from Realtor to Realtor.
Also, as some have stated, it is also not a science and there can be some difference, once again depending on the price of the home in total!
Let me know if I can be of any help!
Kentucky Select Properties