Any offer of cash for keys is probably the best deal you could get as a former owner.
Here is some information from a local atorney. http://www.doctorevictor.com/docs/DOCtrusteesale.PDF
Some of the questions an attorney might ask you:
What are the terms of your lease? Are you compliant on your end? Are you maintaining the property, current on rent etc?
One of the options is to just accept the facts and consider the cash for keys offer. Most offering cash for keys have some room for negotiation.
Reaching out to an attorney with your lease would be the best way to understand your legal options.