Sellers try to limit the grounds for canceling, and inexperienced buyers may sign contracts that don't include common exceptions, such as uncovering major problems during the home inspection, failing to obtain financing and failure of the house to appraise.
Failure to obtain financing is common these days because lenders have become very picky; underwriting is very strict.
Even if your mortgage company is still willing to finance your purchase, the house itself may be worth less than you've contracted to pay for it, and the lender will pull its approval.
With residential real estate markets still slow, sellers usually accept contingency clauses, but if they resist, it may be better to rethink the deal. Losing a deposit of $2,000 to $6,000 on a $200,000 home hurts.
NEXT: 6. Not budgeting for insurance