It's partially up to you...
Boats are not cars. They are women. They make you pay if you neglect or mistreat them. On the other hand, if you give them attention, treat them with respect and TLC, they will only disappoint you every so often and even provide a little pleasure.Many of the problems boat owners have and spend $$$ on result from no or improper maintenance and/or misuse of the system. If you don't know how to use and maintain your batteries, they will not last. If you do not maintain and operate your engine properly, it will break down. If you do not keep your boat clean and washed down, your rigging will jam. If you do not clean your bilge, your bilge pump will fail. Etcetera. If you do not know what you are doing it is easy to do things that can cause big buck failures.I am presuming this is your first boat and you have little experience with them, if I'm wrong sorry about the blather. Before I bought my first boat a couple years ago, an 88 '35, I bought Nigel Calder's book: "Boat Owners Mechanical and Electrical Manual" and read most of it. You can find it at West Marine and BoatUS. I highly recommend it. A big red hardcover book. It covers in detail all the major systems on the boat, and is particularly excellent on the electrical systems. It covers some stuff you probably don't need (I'm not up to rebuilding transmissions) but it explains how everything works and explains how to fix or improve most everything. I feel the knowledge I gained from this book has saved me thousands of dollars and tons of aggravation. Not only that, when you know how things work, you at least have a shot of fixing things when if they stop working out on the water.You should also have a manual for the engine, Yanmar's or Sealoc (the latter being better for novices like me, IMHO - available in on-line bookstores). Finally, make it a point to regularly browse the HOW. I've learned lots of helpful tips on maintaining and using the boat.Even with all that it's a learning experience. My boat seemed fairly well maintained, but after I got it, I doubt that the fuel filters had been changed for years. Both primary and secondary filters were full of crap. The air filter had literally rotted away and been sucked thru the engine. Fortunately Yanmars are tough. I changed all the filters, lubrications, cleaned out the gas tank, and then had a mechanic check it out. Except for a clogged filter, haven't had a breakdown yet (knock on fiberglass). Had I not done this stuff I have no doubt I would have and probably had a messed up engine.I have not had to make major outlays in the 2 years I've owned the boat. Part of it is luck and who knows what will happen tomorrow. But if you learn about and maintain your systems, you should have fewer problems and hopefully minimize the expense involved.