"Isn't buying speakers this way as good as rolling a die?"
Yes. Find a good dealer and work with him, unless you like rolling dice.
well, I just disagree. I DID buy a new set of speaker from a good dealer after spending a great deal of time auditioning them. When upgrade time came, I sold them for half my purchase price. Don't be mistaken, buying from a dealer IS a good option, but don't be confused about the economics. If you are careful, and thoughtful, you can significantly eliminate the risk of used, and end up with more speaker than if you buy new.