Buy some money?

Today Henry was asking me if we could go to our favorite Italian ice place, Ritas, which is also pretty expensive and since I started this all cash budget I tried to explain to him that we needed to save our money to buy real food like vegetables and fruit and that we don't have money for that sort of thing all the time. He then said, "well, we should just buy some more money!". Ha! Why didn't I think of that before?? Genious!!!