The only reason it would be a constant problem would be if you bought a POS, or didn't fix things correctly. Some people buy boats they can't afford to maintain properly and use chitty parts to replace broken ones.
You could buy a nice old flat deck with some good motors (that someone reputable has cared for, not Jim Bob's auto center) TRS drives, and have a worry free machine. The only thing "old" would be the hull, and that's no problem. I had a 76 28ss that I ran constantly and was worry free besides oil changes and putting gas in it.
Just look for an anal owner out there like Too Old and I wouldn't worry about anything.