As to the boat the OP refers to. If I was at the marina I'd ask around to try and find out what the situation is. The owner might appreciate some help to look at the situation, and decide what to do next. eg Its likely better on the hard somewhere than sitting in the water, where it will decay faster and might just sink.
At the end of my dock there is a Skookum 53. No mast, and its been covered with a tarpaulin for the three years I've been there. It has not moved. After a big storm Paul visits to check the bilge is still dry. Otherwise he is never there. Apparently it had a fire inside and needs completely refitting.
His dream is to fix it up and go cruising, but he has neither the time or money to get the work done. Someone contacts him regularly wanting to buy it. Paul's wife is urging him to sell. He refuses to let go of his dream. That's fine, his boat and his choice. But I would like him to get some cost estimates of what it would take - I don't think he really has any idea. You don't, until you are part way though! Once he finds out, he could be cruising years earlier and for less cost by buying a boat in operating condition, if cruising really is his dream.
But, his dream might also be the pleasure and sense of achievement in doing the restoration. If so, he should take it to one of the low cost hardstand yards to await his attention. He owns his slip, but has still paid $20k in maintenance levies in the last 3 years. His slip is desirable (I asked to buy it), and it would rent for $1000/month. He could be $10k ahead by now rather $20k in the hole. Money that could be spent on the boat. It makes no sense to me.