IMO, it depends on the overall condition, the price you paid, and how much you like the engine. If you like it, why not fix it? If you sell it (assuming that you'll honestly disclose the condition), the price will reflect its non-operational status anyway.
I'm sure that others with more knowledge of MTH electronics will chime in with suggestions of other things that you can try. 30-1113-1 is PS-1, so maybe consider other ways of making it run.