We are assuming that you did sign a contract to purchase the home at an agreed upon sale price. Is there an adjustment clause that allows the price to increase or decrease with changing building costs? Is there a financing contingency that could impact the appraisal and therefore open the negotiation for a lower sale price if the appraisal is low?
Is this home being built for you as a primary or secondary residence? How much escrow down-payment do you have at stake? If you would be better off forfeiting this deposit and buying another home elsewhere, your attorney will need to advise you to be sure that you are protected from a "specific performance" action.
If the price has dropped an insignificant amount, try to keep in mind that over time, the value will increase. It is not always possible in buying stocks or buying a home to do so at the exact bottom nor sell at the exact top. Good luck to you.
This can be a problem in times like these.....
If you have concern you might want to consider having an independent appraiser do an appraisal for you to be on the safe side.
The reality is that prices are not only dropping on resales but new construction as well. Your concern is justified.
The "Eckler Team"