I started selling homes in 1980 and would almost always ask the seller to pay for a fee appraisal to set the price. More often than not---the lender would take the same appraisal. If time had gone by since the list datye, the lender would ask the appraiser to review his'her own work and make any adjustments. Wow were those the good old days. My opinion is most real estate people do not know how to properly value a property. I have them try to help me by giving me comps but almost exclusively the comps cant be used. I now consider a pre mortgage appraisal to be worth the paper upon which its printed. It cant be used by anyone else. It would have value for unique, specialty or extra large or small houses though...you would be able to see the process the appraisal went through and what contributes to negative and positive adjusting. ADJUSTMENTS are the largest weak spot of a novice when evaluating property.
An agent should be able to have a very good idea on what a home will not appraise for based upon their study of the related comparables with focus on the SOLD listings from the past 3 months.
In a recent deal, my seller's house did get bid up over $15,000. Since we had done on research we knew that the likely hood of it appraising for that amount was very low. So my seller decided on taking a lower offer but it was all cash and still above list price. That took out the question of needing an appraisal and she was able to close sooner and got a fair price.
If you have an interesting house with unique features that could make the value be higher if an appraiser understood all the upgrades. It would be best to have the listing agent meet the appraiser out at the house so they can explain in detail these amenities.
Now, appraisals are use to protect the person who hired the appraiser; they don't have the subjectivity that they used to. The appraiser is not in the busines of business, they are not looking at it from the point of view of Marketing.
I know that lack of comparables isn't making the appraisal world any easier. I get at least 2-3 calls from every sale from an appraiser to verify and to get further details.