As with buying anything over 20 years old without a good service record, I would have to advise "buyer beware".
The woofers are likely to require replacing. The suspensions would be shot as woofers need to move to "woof". Although the servo-system keeps the woofers controlled, and not flop about like with the usual loudspeakers, that puts additional strain on the Servo-Bass amplifier. If the amplifier has not been serviced recently, it might require a completely overhaul. Unfortunately, as we do not have the schematics for this model (the bank lost schematics and IP when the original Genesis Technologies went bankrupt in 2001) this is not something that we are able to service.
In the systems of that era that we've seen, the original Monster-manufactured servo-bass cables also have to be replaced because of corrosion and deterioration of the dielectric.
In short, it may cost you $8k to acquire these beauties, but it might cost you much more than that to keep them working.