I like to think about the money I pay for a boat as "parked" not spent. I am, or was, a marine surveyor. I have owned boats for the past 50 years. I never purchased one to "make money" on one. I have been cautious so I wouldn't loose money on one. I do most of my own work, from structural repairs to painting to electronics to engine installs. I like doing it and I know it is done correctly. If I could afford to pay to have these things done at a premium yard, I could find something else to do with that time but I don't have the means.
The real cost of a prospective purchase is something you can get help understanding if you can find an honest buyer broker. Brokers don't just list boats. They also represent buyers in the purchase of boats. They know the market. They know the boats. As much as I hate to admit it
some of the best money I have ever spent was on a top professional (read lawyer). A few hundred dollars to get good legal advice is a true value. The same is true of a top professional buyer broker. It needs to be someone you can trust, of course. Someone you have gotten to know and who is known by others you know and trust.
Buying smart doesn't necessarily mean buying cheap or "low". A good boat will return your investment. More importantly it will be a good boat!
You want to enjoy the thing! Every day you spend sailing and not repairing comes off the top.