We dropped in minimarket in Central park, in Batam. We wanted to buy milk powder for my daughter, Nurul, because the stock in home is over. After we picked up a box of milk, we went to cashier. I knew, the price was about Rp 40.000, and I had prepared my money. But…the price is his cashier monitor display Rp 25.000. Wow….the price is very cheap. I thinked, it is the cheapest price of milk in Batam for this size. We we lucky that day. Several next days, we went back to minimarket, wanted to buy the same milk, and the price had become normal.