I just recently bought a set of used System Audio SA2K monitors, and have been extremely impressed so far. These retail for around $3500 new. Quite detailed with great clarity, imaging, and fullness. They also seem to have a bit of warmth, which I really like. Surprising bass for the driver size. If you get a chance, just give them a listen. I highly recommend them. I don't know why System Audio is so unknown in the US, but they make superb speakers. They could definitely use stronger US representation.
As some have stated above, don't equate the best with the highest price tag. It seems that is all too easy to get caught up in the "best this or that under $5K or $10K or whatever." To me it is a reference point, nothing else. Just trust your ears. I have made the mistake of buying component X based on name brand, reputation, press reviews, and price before. All this when my ears told me to buy component Y, and I regreted it later. If you go with your gut (or ears in this case), you will more than likely always be happy with your choice. JMHO