hey! yeah that looked really wrong — my bad.
wasn't a bug or overflow though. i just didn't make it clear that higher stages slap negative modifiers on you, including how much gold you actually get to bank at the end. so you'd see this huge noted total mid-run and then the real banked amount felt like it "broke."
fixed the UI so it shows banked gold properly, and stages explain those modifiers better now. also added some other stuff from the comments by invadingoreo (nested pack selling, gallery or boss drop cards). thanks for the screenshot, that helped a lot