I think you really have to define what you are looking for in a boat a bit more. The range of boats, and the costs will vary depending on what kind of boat it is, where it is kept, what size it is, how old it is, etc.
A lot of this will be determined by what you want to do with the boat. If you're looking for a comfortable liveaboard, but don't plan on doing major voyages or long coastal cruises, then a certain type of boat will be better. If you want a nice day sailer that you can also take short cruises on, then a different boat makes more sense.
You're far better getting a boat that is suited to what you want to do, rather than trying to fit a boat into a purpose it is ill-suited for.
As a general rule, the longer the boat, the more it will cost to maintain, dock, moor, store, haulout, fix, clean, etc. The older a boat, the more likely you are to incur major maintenance costs, like replacing the running or standing rigging
, having a major component fail, etc.
Some boat designs are far friendlier and easier to sail short-handed than others are. Smaller boats are generally easier to handle short-handed than larger boats.
The real answer to your questions is "It depends...".