I agree that you should charter a boat to get a feel for what you want and need. Determine your budget. Plan your realistic goals. Then have fun shopping! My wife and I bought a 28 foot boat four years ago, joined a yacht club north of Seattle, and after three years of cruises ranging from three days to two weeks we bought a 47-foot pilothouse. When we retire in about five years we plan to cruise the Inside Passage from the Puget Sound to Southern Alaska.
We bought a coastal cruiser, and there is no way I would run her down the West Coast to SoCal or Mexico. A blue-water cruiser would have cost us 2-3 times more, and I don't want to run in 20 foot seas. I have been in 8 foot swells (16 feet from trough to peak) and I will never willingly do that again!
We bought a well-equipped boat and have spent nine months adding hydronic heat and fixing lots and lots of minor issues that could have been big issues. You never know what previous owners may have done. The PO of my boat paid a well-known yard to upgrade many systems, and here is a little of what I have had to correct. The flybridge GPS is not connected to the DSC radio, so DSC doesn't work; they rebuilt the davit, then lubed the nylon bearings with petroleum, causing the bearings to swell and bind; they re-wired the house bank batteries but left bare copper wire exposed on every connection. All bare copper has corroded and some wires have cracked, so all had to be replaced. That's the tip of the iceberg. On the other hand I have found several great mechanics and avoided many not so great mechanics by talking extensively with other yacht club members as well as frequenting sites like this.
If you buy a good used boat plan on spending a year learning and fixing all of your systems and getting comfortable navigating and piloting. Spend lots of time getting good at close quarters maneuvering and docking. Too many owners neglect this and marriages get strained when a couple screams at each other while trying to bring their boat in.
My wife loves negotiating and is good at it. We spent months on yachtworld.com looking at boats, spent time on friends's boats, and decided what we wanted. When we found boats that we liked we made offers through the seller's broker. The first three boats we made offers on countered our offers with unrealistic numbers, so we walked. The fourth boat we made an offer on, the broker knew who we were, knew he would get both ends of the commission, and gave the seller advice on accepting our offer. By carefully shopping, buying in the fall, and knowing the actual sales price of the last six comparable boats, we bought our boat at a solid 20% below market.
Wow, sorry for the long post! There are so many variables in your equation there are dozens of decision points for you. We learned so much in our $20,000 28 foot boat that helped us transition to our 48 foot yacht. You may not want to spend a few years doing that. Make friends with people living the life you want to have. Spend a few weekends with them on their boats, pay for all the food, booze and fuel, and learn how to dock a boat. You'll find out quickly what you will want in your own boat. Good luck!