My wife is looking to buy a used DSLR in the $300-600 range. What's the best bang for her buck. I guess she should be concerned with image quality and availability of accessories? I know nothing about DSLRs and she hasn't been into photography since college. So far I've run into a few Canons (350D, 10D, 20D, 30D) and some Olympus E-510s in that price range. Are these good for a beginner? She'll mostly be photographing people/models if that matters any.