In fairness Prof it's not quite applicable in this case but I know what you mean, I have mitigating circumstances, I was watching inglorious bas$%rds today so on the mind.
apologies for my stab at humour, not very helpful. As for the reference to unmatched speakers you need to contact the seller I think and find out how exactly they are unmatched (and if you wont be able to listen to them before buying I would personally steer clear).
To expand further. Mass producing any component, you're never gonna get exactly the same item every time. Matched speakers are pairs of speakers (or more accurately, the drivers within those speakers) which have been paired as closely as possible by the manufacturer from data obtained by test bench analysis.
It could also refer to the finish on the veneer, but I would have thought the seller would have mentioned a cosmetic mis-match.
I wouldn't call it a deal breaker though. The drivers in a centre speaker in a home cinema set-up won't have been matched the the stereo pair from the factory, obviously, but whether you'd be able to tell the difference in a stereo pair only you can decide.