It depends. If you want to keep the property then its worthwhile to do what you can to get the balance lowered. Real estate markets are different from month to month and year to year so I wouldn't be too sure that any of the appraisers was wrong. However, you do show a large discrepancy from your appraisal to the bank's. Appraisers can justify their conclusions many different ways. You might get some feedback from your appraiser and learn how that person views the newer figures. If he gave you an intentionally low figure, you might not have a reasonable expectation of what to expect from the lender.