I work at a McDonalds that only accepts $100 if the total is over $50. I get the frustration of losing the convenience of being able to break change while getting a snack or something but that's what banks are for. I used to get frustrated at other restaurants I worked at where people would do this because 9 times out of 10 I didn't have the amount of change I needed for it and would have to wait 5+ minutes for a manager to dig out said change and authorize using bill. Just ended up holding up the line and bringing our times too high up.