Buying used or sight unseen speakers a bad idea?

You generally start building your feedback by buying couple of things. Yes, feedback as a buyer and as a seller are not quite the same, but at least someone already did business with you. I bought and sold a lot on ebay especially records and cds but not much here, just a dozen of items.
I am a good guy too - if the the price is right.

Not much to add. Just to say it again - never from people with 0 and perhaps only 1 feedback unless someone you trust reasures you that the person can be dealt with safely. Not even if the speakers are free.
Even better approach. Buy only from those who participate here and whose posts are at least okay with you.
And, yes, unless it is something very rare and unique, or virtually new, never pay more than 50% the retail plus shipping.

Why would a woman need M5? Either M3 or Porsche.
Anyway, modern cars are computers on wheels and computers sometimes have minds of their own. Good for us that speakers are much simpler so far and it is unlikely that they could go into reverse.