All in one sitting. You get one condiment of choice, and a large glass of water. Bills can be torn up before consumption but nothing is stopping you from housing full Benjamins and digging for gold in the bathroom later. I think I could probably eat at least 10, and I would pick BBQ sauce.
That’s for raw potatos and you assume fully water-free bank notes. While I couldn’t find how much water a cotton-fiber blend would draw from the surrounding air, I found the water content of potato chips to be around 3%. Eating the equivalent of 4-5 regular sized bags of chips with barbeque sauce sounds absolutely doable. Not pleasant, not healthy but definitely something I’d attempt for 50000 bucks.
You’re right that I’m assuming bank note moisture is negligible or sealed, which may or may not be the case in practice. However, raw potatoes are 79% water and baked potatoes are 75% water (re-reading, I see that I didn’t actually say baked, my error).
My source for 3% water content in potato chips: Module III Shelf Life Testing of Foods Chapter 6 - IUFoST which roughly matches the results from this table in Tarmizi, Niranjan - Combination of Moderate Vacuum Frying with High Vacuum Drainage—Relationship Between Process Conditions and Oil Uptake. Could be wrong though, I’m not a food scientest, just a guy who likes to nerdsnipe himself.
The source I linked has a similar water content for potato chips, no dispute there. We could say that stack of 500 Benjies would be like eating 2 full bags of potato chips (an amount that would be 2,500+ calories of chips, for scale) with zero water, if you’d prefer to imagine how your digestive system would fare with that instead? Whether fried or baked, all I’m saying is it would be ambitious. :)
For enough money to use as equity on a loan for a house, I’ll gladly suffer for a few days.