A flat fee to list and what the realtor does for you depends on the company they work for. Some put in a small amount of effort such as just listing it in the MLS, while others put in a lot of effort in by not only listing in the MLS but also contacting all realtors in their network, telling homeowners in the area who may have friends who want to move in the neighborhood, and advertising to large companies in the area who may have employees transferring in from out of town. I hope that helps.... more
Technically, in part, it depends on the reason why the seller is backing out. You're suggesting that the financial contingency has been satisifed. But are there other contingencies that haven't been? If so, then the buyer may be entitled to the return of his earnest money.
Assuming, though, that the buyer has simply gotten cold feet and that you're 100% in the right, you could play tough. Or you could negotiate. Ask your Realtor for advice on that. There's also the question of re-marketing the property and how a protracted battle over the earnest money might affect the timing. Again, your Realtor can advise you on that.