I always imagine an unspoken "at a certain price" when people say they believe in buying locally. I live a short distance from a grocery store in my neighborhood, but I rarely go there because I like to cook and their prices for meat and produce are always higher than the big chains. In the case of their meat the difference has sometimes been as much as $1.50/lb. which is huge if you're someone who prefers a frugal lifestyle.

Edit: As for condoms, I think the situation is a little different. They ruin sex compared to going without a condom, marketing from Trojan be damned. I'm not trying to endorse the mindset, but there are many people who are primarily just trying to avoid getting someone/themselves pregnant so if someone's on the pill that's good enough for them.