We buy organic foods when we see what we eat at a regular grocer. We occasionally will shop at a Whole Foods, but the local Super Fresh, and a local chain both sell organic meats. Their selection varies week to week so you can't count on them having anything in particular when you go.
We buy organic foods for a couple reasons. First, they're often produced by small farmers looking for a niche to stay in business. They'll use more labor intensive methods for weed and pest control, so the costs of production are higher then the farmer using aircraft to spray the crops.
The second reason we try to buy organic, and this is especially true for chicken, egg and pork productions, is the animals are treated more humanely, given more room to live in, and not treated with antibiotics to simply make them grow faster.
Those antibiotics that we need a prescription for as a human are available over the counter at your local farm supply. It's my belief that it's that use of antibiotics that leads to the decline in the effectiveness of the antibiotics in general and not the misuse by humans as you'll here described in the press. Antibiotics are used in HUGE quantities by the food industry, and we don't want to support that misuse if there are alternatives.