Well, you could get a thousand responses to those questions and become very confused. I would.
Your assessment of cost is absolutely correct. Boats cost - lots generally.
But a boat is not just a thing, it is a way of life and each boat has its own personality. They can be reviled or loved and the first purchase is either a learning experience or something that will turn you off the water for life.
Unless you are very lucky the first boat will not suit over the long term but, if you choose fairly well, will give experience and eventually lead to the boat that suits.
I have regretted buying only one boat because of a hasty decision brought on by a (perceived) pressing need to get back on the water. Some of the boats (and there have been many) have been owned in partnership with my brother. That partnership worked very well but I could not imagine entering a partnership with any other person.
I have never thought of hiring or entering something like time share on the basis that a 'relationship' could not be formed with the boat.
A boat lives, it is a companion and a friend. Someone to talk to when everyone else has abandoned you.
They make a very comfortable dog house at times and don't mind if you have had one beer too many.
Unlike someone I could mention, but won't because Mother's day has just gone by.