I bought a pair of them from a pawn shop in the early 80's and paid $150 for them. Kept them through the rest of high school and all of college (great party speaker). Sold them when I bought my 250Ti's. For $1500 a pair or less I'd buy a pair for my gym. I can't imagine they are worth $4000 though with all of the other great speakers out there in that price range ... Just my opinion!
If Harmon wants to play on nostalgia ... why not bring back the Infinity IRS Beta's? Heck for that matter what about some Kappa 9's so we can use them to test amplifiers?
