Last year I arrive 11am and get in the store at 12:30pm. Finally wait about 20 mins for paying the money. I already know that it is kind of "Wan Bun" ! You can probably save around $100-300 in total compare you buy in Mongkok. But once you calculate it, you will know that you have to spend almost 3-4 hours for saving $100-300. Is it really worths to do it ?