We were very young when we were married (19 and 21 to be exact) and planning to live aboard and voyage via sailboat someday. Note--while many cruisers plan on sailing off into the sunset, not working, and not spending a lot of time in their home country, that was NOT our dream. Our dream was to be able to live aboard a boat anywhere (obviously coastal) in the USA and world-wide while working (or not) as we see fit. We're somewhat location agnostic and we love being a productive part of society and expect to be in-and-out of productive jobs until we're in our 90's.
1. We never planned on making payments for a boat. Our number one criteria in life has been to live within our means. Though we both put ourselves through school by working, we did end up with some student loans and paid them off in about 5 years. Besides real estate loans, we've only personally borrowed for one car (in 1985) because it was a great interest rate deal. We've never carried debt and don't recommend it. We didn't plan on purchasing a large vessel--our dream was a 30 foot cutter. But, back in 1982 when we were planning our voyaging life, 30 to 36 foot boats were the norm. Now, people routinely voyage with much larger (and more expensive) vessels. If you dream of a small vessel that can do what you want it to do, if you happen to have the funds to purchase (and maintain!) a larger vessel when the time comes--great! you won't have gotten your expectations up too high.
2. We believed that the single thing we could do to "bullet proof" our budget and our ability to independently voyage indefinitely was to be able to fix EVERYTHING ourselves and to be innovative about methods and materials. So, when we had something that needed fixing on our car, lawnmower, house, whatever...we learned how to fix it and fixed it. Period. When the part cost $500 and we could fabricate it for $50, we did. Period. We thought the ability to learn to take care of oneself was critical to our success. We were right about that. If you are not DIY people nor have the desire or ability to learn, budget in a good amount of money for maintaining your boat. Our DIY skills included every range of maintenance skills we could learn--the only thing that neither of us is truly proficient in is welding (but we've never had to be) and our DIY skills include excellent cooking/canning/baking/drying/ as well as sewing/upholstery/leatherwork and boat specific rigging skills.
About sailing skills--we took sailing lessons early in our life together and taught sailing for a couple years (which enabled us to rent the boats at the sailing facility very cheaply or for free) to pick up our experience. That was all in the 1984-1990 timeframe. We later did a lot of small boat sailing/canoe sailing because we could easily own a sailing rig for our canoe! but only sailed on bigger boats owned by friends or charter. When we sold our house in 2006 and bought a big classic boat (a 1931 29 ton schooner to rebuild and voyage on) we simultaneously purchased a small boat (a 1966 Rawson 30) that we could sail on weekends and evenings between working on the big boat projects. The smaller boat actually was a great cruising boat and would have fit our "dream boat" from our early 1982 plans. We had a lot of fun on it during the time we owned it before selling it and relaunching the boat we now live on. Sailing a lot of different vessels and sail plans is helpful in building confidence and making yourself comfortable with your final boat choice.
You don't mention whether your husband actually sails. I've met experienced motor boaters who live aboard sailboats that they cannot sail. Amazingly several. Hopefully your husband did a bit of sailing. Oftentimes when folks liveaboard, they don't go anywhere because it's "too hard" to put everything away and so forth. Motor yachts and sailboats are VERY different vessels. I know several folks with USCG 100T (or larger) masters licenses who have had successful careers captaining motor vessels of all sizes but they are NOT necessarily qualified to even sail a Laser. You (and your husband) don't necessarily need formal sail training but it is often easier to get the experience you need if you take enough coursework to be able to charter sailboats for your vacations. You do need to know that sailing (not motoring) is really the thing you want to be doing. You'll only learn that from sailing. If you love sailing, sailing it is. If you don't love sailing, you might consider the options of owning an appropriately sized trawler or other motor yacht that will enable you to travel to the places you'd like to go. Sailing is romantic and certainly "green" but not necessarily the right choice for everyone and not necessarily any less expensive than using a motor yacht IF you're not a good sailor and end up motoring a lot anyway.
I'd suggest you have a goal, make a plan, try to stick to it. If you're not able to budget now, you won't be able to when cruising. If you're not willing to be DIY-folks now (home/car/cooking/cleaning/sewing/lawnwork/cleaning gutters/etc) you're unlikely to be willing to do so on a boat so you'll have to budget for maintenance expenses.
It sounds like you're older than we were when we went on our 25 year plan
and certainly, your husband is. So, look at what you've done happily and what he has done happily--make your goals and dreams fit into the people that you ARE not the folks that you might be if you "try". Things are much different when one is young as we were. Young and stupid--you think you have to take on the world and you think you must learn all this stuff...you just go off and do it. It's truly harder (I think) if someone is older and doesn't have a DIY mentality to start with. A willingness to learn is always great, but don't beat yourself up if the DIY person isn't who you are.
Best of luck in finding what will really work for you and your husband!