Miner's Hut 1 3$
(only available if there a Prospector role)
Take an additional doubloon
How will this work in a 5p game, where there are two Prospectors? Make sure it isn't too strong.
Colonist's Tent 2 6$
Get an additional colonist
Definitely too weak or expensive. For $7, the Villa does the same thing, and each such colonist is worth a point.
Diamond Mine 3 8$ (Production Building)
Give 1 VP per working colonist
Absolutely too strong. Imagine a typical game where a player produces a modest 5 goods. That's 10VP just for producing.
Bank's Vault 4 10$
1 VP per 3 Doubloons
Far too weak. I've already developed a Bank large building that grants 1VP for each 1 doubloon invested into the Bank (though it takes a little effort to invest). My point is that a previous version granted 1VP per 2 doubloons and that was still too weak.
Storage Hall 4 10$
1 VP per 2 Goods
It would be easy for another player to pick Captain right before the end of the game to cause you to ship your goods, and miss out on the points. It's too unpredictable in that sense; and 1VP per 2 goods seems weak anyway.