I'd try bending it back. Maybe screw a 10x1 bolt + nut into it as tight as you can get it fastened down first,then try bending. Will the 10x1 actually screw in without cross-threading now? But, I don't have a lot of faith that you'll successfully preserve the threads.

And, I'd never sell a frame that I had any belief that the derailleur hanger wasn't 100% up to snuff.

So, with that in mind, it is probably a fixie project.

Or, I might try replacing both dropouts myself (you'll probably have a heck of a time finding just one).