1. First - read your contract beginning to end - seeif you can find any "outs"
2. Assuming you have an agent, bring them into the discussion......
3. If you don't have an agent, or even if you do.............as mentioned by others, you need to check with a real estate attorney to see what options you have - legal options - that won't put you on jeopary of being sued!
4. When all else fails, you may simply try to ask the buyers to let you out of the contract - if need be, even offer some monetary incentive if you really want out that much. You didnt say how long you have been in contract with the buyers, but perhaps they will be sympathetic to your reasons for wanting to remain, if you explain it to them, , and will work with you..........as i said, sometimes money can help people see things your way!
Other than the above suggestions........I can't think of what else you can do...............other than pray the house doesn't appraise out!
Oh, and do not forget to bring an attorney into the picture - you must make sure you are covered legally.
Prudential NJ Properties
I think it's safe to say that you probably don't have much of a legal ground to stand on by not going through with this deal.