This is something I went back and forth on for a LONG time with my last boat - a '64 Silverline Riviera. In other forums, there were many posts of "ton of money into old boat, not worth, find another hull". Problem on the other side is that it turned out to be an impossible task to find a sound hull within my budget, that didn't have some level of rot. The vast majority of boats that I looked at needed the same level of work mine did - complete gut and rebuild.
Granted, my budget level likely is much lower than most other people here, also likely toeing the line of "I'm too broke to own anything beyond a rowboat", lol. I can't speak for the value of your particular boat, or whether it's worth it to repair. I think a lot of it is very subjective...what's worth it to one guy will be a complete waste of time and money to another.
In my case, I ultimately decided that an old tri-hull fiberglass runabout wasn't worth putting more than $100 in to, parted what I could, and scrapped the rest. The next boat I bought was an '85 Bayliner Bass Trophy, and I went in to it knowing it needed at least a redecking, replumbing of the live wells, and some electrical work. All told, I'll estimate I'll have somewhere around $4,000 in to it, including purchase price.
But on the other side, even $4,000 isn't going to get me into a clean boat without rot or maintenance issues around here (Phoenix, AZ area). While I haven't looked extensively, I suspect that a lot of it is regional, in that in many other areas where bass boats are on every corner, this probably isn't the case. But either way, at the end of all this, I'll end up with a boat set up and configured the way I want it, for less money than what it would cost to buy one without rot issues...so to me, my boat IS worth putting the time and money in to, whereas I'm sure there are many others who hear "Bayliner", and will think it's not even worth using as an anchor, lol.
