That's a genourous Dad, there!
Re: big bills & cheap eats- I was on a trip to Europe as a teenager- back in the mid '80s- and at the time we were in Italy. After getting some Lira for our Dollars and dropping off our luggage, we headed into the streets to start seeing the sights.
I decided to get a gelato from a street vendor. I got my cone, and searched though my cash to pay the man. In my inattention at the bank, I didn't realize how big the bills I was given were. The smallest bill I had was roughly equivalent to a $50.
The vendor gave me the stink-eye, but I had no lesser Lira, and I was already eating the treat. So he had to close his cart to go into a restaurant to make change. Through the plate-glass window, I could see there was much gesticulation twixt him and the cashier in my general direction.