You can check your contracts, you can talk to an attorney, and you can decide also what is most ethical. If the listing agent, at their own expense, provided you marketing services to make the buyer aware of the property, presented the property in the best light, provided you the correct services to expose the property...you can determine whether they had earned compensation.
You can also decide whether you want to proceed with a sale unrepresented.
50% of a deal is in making sure your transaction is legally compliant with the CA Dept of RE (both federal and state laws), that you are protected in the transaction should the buyer decide to contest the transaction later. (like on something you didn't disclose).
First part is: are you under a contractual obligation to pay one of your real estate agents? - Yes, in California, the obligation or the expiration of an obligation is probably addressed in the old listing agreements. The Connecticut agents gave a good answer that works in either state.
Second part is: do you have a moral obligation to compensate the agent(s) responsible for attracting the buyer in the first place?
Third part is: Do you have reason to trust fair dealing from the buyer whose contact with you discloses a plan to buy at deep discount from you? It is to the buyers advantage to persuade you to think that you will save money by not being represented.
Cash Buyers expect to buy properties for less than they are worth.
Fourth part: If you know what your house is worth today, Is the cash buyer willing to offer 100% of value or even 94% of value?
If he is not offering at least 94% of the current value, then you could lose badly by leaving yourself unrepresented.
We would suggest that you go back and look at the two real estate listing contracts you signed. Each company handles this differently and the real estate contract expressly outlines the company's terms. If you are still unsure, we suggest that you consult with your local real estate attorney.
Bob & Richelle Ward, Realtors, ABR
Prudential Connecticut Realty
cell: (203) 470-9818
If it is a freah customer like your neighbor I would still contact a agent and try to work out a reduced commission to let him handle the sale. There is to much to do for a homeowner to sell his own house. Better to pay some commission and let the agent handle it.