Sorry about the wording. At the time it seemed nice to separate out +1 Buy.
I usually Borrow turn 1 or 2. I never feel bad about that, but sometimes feel like I Borrowed too much later. Obv. you do it late-game any time it does you any good.
In games with Militias, it's tempting to constantly Borrow. Take that, Minion. But it's a combo with Minion too, so it evens out.