I am very, very fortunate to live in an area that offers so many choices for grocery shopping. A bakery, a farmers market, a butcher, a fishmonger, are all within a few minutes of where I work and where I live. This makes it easy to shop daily, and to buy small.
But even without these choices, buying high quality and the right quanity is possible, especially if you make friends with the butcher. All the major grocery stores have a butcher on site, and it pays to chat. At first, it might seem strange to strike up a conversation with the butcher. After all, the goods are already packaged and in the case, so what's to talk about?
Well, ask the butcher about his best quality product, or the best cuts, or ask for recommendations. I've never met a butcher who didn't like to share his expertise! You can also ask him to halve larger cuts or repackage items. Get to know the butcher well enough and soon you might be asking "Can I order two of your best lamb chops for tomorrow?"