What do you qualify as local?
I'm in the DC area, and there's a farm from Pennsylvania (Twin Springs Fruit Farm) that sets up a farmer's market near my work each week. I'd rather shop there because they have good food, but I don't know if I'd call it 'local'.
I'd like to buy from more local farms (within 10 miles), because I want them to stay profitable, so they don't turn into sub developments like what's happening to most of our area. (Upper Marlboro, MD). We're working on setting up a farmer's market in the area, but the location we had scoped out took 9 months to be repaved (stamped concrete), and we found out in May when it was almost done that we weren't allowed to have vehicles on it for 12 months.
As for organic, I couldn't care. I'd also rather shop at a small grocery store (hispanic/african/asian/"amish"/etc.) as they're smart enough to mark down the food when it's not selling, so it sells before it rots. I can't say the same for the Safeway/Giant/etc in my area who are trying to sell vegetables at full price past the point where I'd even consider it for soup.
So, I guess, more criteria to add to the decision : Taste , Freshness, Small Business (and then for me, Local, Price ... and Organic falls somewhere below Packaging, as I refuse to buy eggs in styrofoam containers)
And some of these things might be weighted -- there's no way I'm going to get local citrus, and I might be willing to pay a premium for small businesses, but it's not 200%. (well, maybe for the white peaches, or a really good sourdough bread ... sometimes you just have to splurge for the things that really matter to you)