Why do people keep saying there are officially supposed to be infinite basic treasures, when that's very much not the case now, and never was? Donald X has said, on one occasion, that ideally the basic treasure supplies would be infinite but real world constraints mean they aren't. In fact, I can't even find a link to him saying that in the DonaldX section of the forum.
But That's VERY different to saying the basic supplies are supposed to be unlimited. There are supposed to be 40 Silvers, 30 Gold and 32-46 Coppers in the supply - an amount which is essentially unlimited in 98% of games, but occasionally they run out - and the rules make it very clear an empty basic treasure pile is still an empty pile.
Compare, if you want, to Thunderstone, where the Plague (~Curse) cards ARE unlimited, any trashed Plagues are returned to the supply and if they run out, you put a suitable replacement card in it's place.