well, you haven't specified anything (beyond the bluewater/circumnavigation requirement) on the kind of boat you are looking for, and certain items in the wishlist can change the search results considerably, but, a quick search of the market shows that under $150k, you can find:
multiple Fountaine Pajots (Athena 38, Tobago
40), some of which have been chartered, others, privately owned;
a few Nautitech 395s;
a few Edel 36s;
and a number of custom builds, one-offs, etc.
Of course, each one of these would have different requirements, repairs
, other potential expenses, so it's hard to generalize. If you go under 100k, you might still find a few gems, but from what I understand, you want to limit the amount you want to spend repairing/updating/upgrading, which means a higher beginning price
Between 150k-250k you have a huge range of options, some of them just a few years old, and apparently well-cared for. In that case, you'd be looking at a 10-year plan.