Value of Acoustic Research AR2's

I'm looking to buy a pair of Acoustic Research AR2 loudspeakers. (Not the AR2a or AR2ax, the original AR2 speakers.) I'm not looking for something that is in mint condition or has been fully restored, but something that's original and still fully functioning. (So, it needs to sound good, but it doesn't have to look great.)

What's the range of prices I should be willing to pay?

Thanks!