The milk cost 20$ for 10 (2$ for 1) but sells for 1$ per item ???
The reason it's important to have enough customers in the beginning is that you've got to pay the rent. Once you're selling a lot and making a lot of money it's such a small share of your expenses that it's really not important. In the beginning however it can make you go bankrupt.
Thanks! I doubt they will ever see your reply 3 years later but this helped me :)