My first rule is to never buy new - whether it is cars or speakers. By the time you get them home, you just lost maybe 20% and with cars, by the one year point, 30-40%.
Better to buy them used because you get more for your money no matter what level you are buying at.
Whether that saves you $2000 or $20,000 on speakers, that is money you can put into other elements of a system.