Tried it out. Nice little deckbuilder.
I liked the progression mechanic, but the four-cost cards might be too powerful. Once you get a couple of them in your deck, it quickly becomes trivial to make quota and churn a lot of coin. But it was certainly fun getting to that point, and the little puzzle of how to get over that hump was enjoyable.
I'd love to see this with more art on the cards, more cards to buy, etc., but maybe that's beyond the scope of what you're trying to accomplish here. Either way, I sure liked what was here, and had some fun with it. Great work!