This is a store where people GIVE away their stuff, out of the goodness of their hearts with the premise that it will be sold at a low price so that someone less fortunate can benefit. If goodwill has decided to sell the merchandise it gets for FREE at “fair market value” to the highest bidder in order to maximise profit then what’s the point of goodwill? Might as well use a consignment store and get a cut.
The exchange in “Goodwill” is that you’re donating in goodwill so your things can help others. That’s what goodwill MEANS.
You can sue for anything. I can sue you for trespassing in my home because your message is in it right now. Suing someone doesn’t mean you’re right or that you even have grounds to sue.