Grocery Club Shopping

I'll run to the corner store to buy a lot of my food and drinks. Nothing has a label on it, and prices are doled out by the counter guy on an arbitrary basis. A guy in front of me will pay $4 for a huge can of Fosters, and then the clerk will charge me $9 for a six-pack. Pleased with the deal I've been given, I'll return and get the exact same thing the next day only to be charged $12. I'm pretty sure the clerk just charges whatever he wants, so lately I've been laying down however much money I think he should charge me and then seeing if he says anything. These little grocery stores may not have all the fancy clubs with special rewards cards, but you can find ways to get good deals.