My understanding was that your long term goal was to live aboard a Cat?
That you were considering living onboard in Japan
and supplement acquisition cost by using your corporate living allowance?
If so, then stick to the size you feel comfortable with and look for a boat that will meet your ergonomic needs.
Take your time to study the used market and do searches with local brokers in remote
areas of the pacific, whose owners are seriously motivated to sell.
If you are successful, then the delivery
is not a big deal if you do the same level of research
on transport solutions
Whether this boat becomes your last or first is impossible to tell as so many unknown factors will come into play.
So why pay a premium of new for something not completely defined, when you can explore the used market as a test of your primary life choices?