I've recently helped rebut an appraisal for a clients refinance. The data the appraiser used was from 2012 and they used a pending price which was $100K under the sale price. (local agents often have this information) The mortgage broker asked me for very speciific data, list to sale price, all closed sales in a particular area and any other information I could provide as a local agent very familiar with the inventory. A local mortgage broker and a local agent can be a big help if you're trying to do this!
Sometimes, the listing agent, the buyer and the buyers agent can write narrative reports to
explain why they are all in agreement on the purchase price! Buyers looking for months in a particular area where there is zero inventory are going to pay a premium.
When an appraiser calls to set up an appointment, you may want to make sure they are familiar with the area. I think they have a very hard job.... value is never just in the data!
We have been successful rebutting a number of bad appraisals, but there has to be something you can point to that is wrong about it.