And, depending on your goals, you can cheat horribly. Years ago, when I was more interested (since there weren't many alternatives) in the physical ownership aspect, I usually just picked a cutoff of a couple of dollars. Looks interesting and is under the target? Mine.
Strictly speaking, you'll probably overpay a bit, but if you think about the time to look things up and make a rational decision, it could be a wash. For me, that kind of shopping is painful enough that it's worth a few extra dollars.
