My advice to you is:
>1) Call a Real Estate Board Certified Attorney.
>2) Call a Real Estate Board Certified Attorney.
>3) ...I think you know what I am going to say here...
Once you sign a contract and agree to sell the house that you had advertised, you have made a commitment to sell it. There are no "outs" for a seller. That's why it's called "an agreement".
Since it has been less than 10 days since you agreed to sell your house, one has to wonder why in the world you would want to buy it back! (It would have helped us answer this question if you had supplied us with a reason.) You should obviously consult with your Real Estate Agent/Broker. (If you don't have one, "FSBO", then you have gotten yourself into a real mess, and definitely deserve to pay an attorney his fee.) Your Agent may be able to work something out with the buyer's Agent, and it might cost you less to settle with the buyer than it would to hire an attorney.
...But there is no "free out" once you have signed a contract. That's why we always ask if you have any questions before you sign the agreement.
I can't imagine why you'd want to keep the house now that you've found a buyer, but it must be a desperate situation for you. I am sorry. Try to have an open discussion with the buyer and the two Agents, and I'm sure you'll be able to work something out to everyone's satisfaction. (Don't forget: You've agreed to pay the agents' commissions, in addition to compensating the buyer for his time and troubles.)
ULTRA Real Estate Services
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