I'm sorry, I guess I was not clear about making an appraisal. What I meant to say is that you should look at the comparable information and analysis supplied by the agents that are known for getting the job done. Did they use sales from your area and adjust for condition and size? Did they use sales from other areas and adjust for location? Did they consider the same sales or did they look at different sales? These folks have all told you your house is worth less than what it was listed for. After you look at the sales they supplied, do you agree with their estimated selling prices?
The same thing is true for market rent. You have to investigate what other homes in your neighborhood rent for. You want to call on for rent signs, look on-line, and call a couple of property management companies for their opinions.
At the end of your research and analysis, you should have a good idea what the house would bring in a sale and what it would bring in rent. With that information, you can make a better decision. For example, if the house would only sell for $90,000, but it would rent for $1,200, it might make sense to rent it out and move. You could come reasonably close to break even if you are willing to be a landlord. However, if it would only rent for $700, then you might want to tough it out until the market recovers. You will lose several hundred dollars a month on that deal.
The problem with lease-to-own, especially in a marginal neighborhood, is the quality of the people that want to do this. These deals work well in desirable neighborhoods with folks that would be well qualified except for a recent short sale or bankruptcy from medical bills or other unavoidable circumstances. These people have stable jobs and a desire to own again. You don't get many of these people in marginal areas.
I don't think it is necessarily wrong to take a hit to sell the house and move on, but I would want to know all my options and the likely outcomes before I made that decision.