Why can't I build Size 3?

[davypi]

https://boardgamearena.com/tableview?table=850196623

I am Davypi in the linked game. I am taking a level four build action, but when I do this, the size three building is greyed out with a red X on it. I have two places where I can legally build a size three building (left side of map). Why will it not let me do this?

[rautisbebetsu]

Because you dont have money

[davypi]

Derr... I've head enough cash for most the game I haven't had to worry about it. TY