Do some simple math...add rent, utilities, insurance, staff, stock and your salary. Divide by how many days a month you will be open. If you think you can generate that amount of revenue every day, you could be on to something. For the sake of argument, let's say your overhead is $5,000 a month. You will be open 6 days a week, 24 days a month. That is about $190/day of sales/income. Every day; day in and day out. At a minimum. Just sayin'.