When a buyer is in breach, a seller might sue for specific performance. More common is a settlement for damages. The amount may result from the terms of the contract, a negotiated settlement, or a legal action.
Are there any contingencies that would allow you out of the contract? Are you trying to back out as a result of an inability to secure finanincing, or inspeciton issues?
None of the above is legal advice. You will need to reveiw your contract w/ an atthy to determine your options. The above info was for discussion only.
Bottom line: You can not force a buyer to buy. It is possible to sue for damages, lost market time, specific performance, etc, but it seems that the courst have not been very strong on this and simply award the earnest money to the seller.
I am not dispensing legal advice here, and I would certainly consult with an attorney on this matter. Belos is a link to the possible remedies of contract breach in the state of OH.