Sufficient Sufficiency?

I don't have anywhere near enough space to be self-sufficient in everything, even for just the two of us. However I think that with some experience I could get reasonably self-sufficient in herbs, leafy greens and summer squash as they're all fairly easy to grow, as well as being good value for money/effort involved. For the rest, it's just nice to have tomatoes fresh off the vine and other zero-food-miles additions to the larder.