Time flies, but the newest 390's made are all over 20 years old now. Your ownership costs will vary depending on the cost of storage (both wet and dry), insurance and to a large degree how much of the maintenance you plan to take on yourself.
My parents own a 390 and their operating expenses are probably about as low as you could possibly get at around $10-15k per year. This includes storage, insurance, recurring maintenance as well as a moderate repair or rebuild of a system each year. For example, last year the flybridge between the two benches that face each other (under the table) needed to be re-cored, my mother and father did the project themselves. My father remains very capable at 78 (and I won't share my mother's age), he is slowing down a little but still far more likely to take on a project prior to hiring it out. The year before that, the single Yanmar was due for intercooler and head exchanger service, which he performed himself. One or two years back, the generator needed a new head gasket. They keep the boat at a very reasonable marina in Solomons, MD. This approximate cost does not include fuel and transient dockage costs, as they vary dramatically with usage.
We happen to be a Mainship family, and I have an old 34'. Interestingly, my operating expenses are very similar to my parents, my boat is a bit cheaper to insure and I keep it at what I consider to be an upscale marina so our costs even out. My boat requires annual projects to keeper her operational, a bit larger in scale but still pretty affordable because I'm not paying for anyone else's. It is nice to be able to lean on each other's experience and for a hand, plus we always have something to talk about or plan. I have quite a bit of fiberglass experience and some mechanical experience as well, my father is less thrilled about fiberglass work, but he is perfectly capable and digs right into it and is capable of taking on any mechanical project. He can keep himself pretty busy helping friends keep their boats operating over the season.
