My boat cost 15k sterling and in the first year I put um, about 6k into it, which included new rigging and a tonne of new engine parts like raw water pump, starter, alternator.
I'm hoping that 'normal' years will be a lot less; am thinking I'll need money for spares only; hoping;praying.

I think that once you have a boat, that is when you start to prioritorise and realise that many things can be put on List D and other things can be done with the help of friends, which helps to keep costs down.
Before I moved to my boat, I had huge lists of things I thought I should do. But once on the boat, I was less paranoid and only focused on what it would take to keep the boat afloat.