In a game with Idols and Trader, and lots of +buy, both my opponent and I had trashed all of our Estates, and I'd gotten one curse, while my opponent had none. There were two empty piles, and one (Engineer) with 4 cards left. Near the end of my Action phase, I had 4 buys and a total of $15, with two Idols, a Trader, and the Curse I'd gotten earlier from their Idols. My last Action of that turn was to trash the Curse with my Trader. Then I played my treasure, gave my opponent a Curse with my Idols, and bought all four Engineers, winning the game with a score of 0 to -1! My opponent had a much stronger engine, so if I hadn't managed to end the game there, I would surely have lost. But I managed to end the game before their engine could kick off