Double or nothing Chinese food

Today a Greek colleague of mine took me, our French exchange student, and a visiting Greek professor from France (yes) to a Chinese restaurant with a peculiar system. If you order ankake yakisoba, their specialty, you pay 682 yen for "normal size". You can also order "large" or "enormous", and these sizes will also cost 682 yen if you finish all your food. If you leave something on your plate (or give food to your friends), you will have to pay twice the normal price instead.

Even the "normal" size was pretty large, but the two Greek guys ordered the middle size ("large"). Both managed to finish their meals. I ordered something completely different, which was also good.