The sellers might try to challenge the appraisal, and that could work. However, if you're obtaining a mortgage, the bank will only give you a loan for the value of the appraisal, so it's going to be up to the sellers if they want to proceed with your contract or not.

The appraisal is what it is. You can try to find comps in the area to up it but in this market appraisors are using caution which they should. The market is declining so that's why some places are coming in lower than expected. The seller should be happy to have an offer, the price isn't off that much. Hope that helps.