how much to pay for this sensational setup?

not an audiophile..just purchased a house with this setup and the owner wants to sell it off....what is this worth you think?

B&W 801 speakers (UK)
B&W ASW300 subwoofer(UK)
B&W DS6 centre speaker(UK)
Sony Blu ray player
Krell stereo amplifier (USA)
Marantz 8003 power and pre amplifiers
NAD2400 power amplifiers.
Krell speaker cables. (these are currently around $700/meter
what is this worth you think?

Whatever you can find someone willing to pay for it.
Not more then $3000. Since you are not into audio, treat it like a used car being taken in at a dealer.
What series B&W 801 and what model Krell amplifier? The condition is also a major factor.
Post removed 
Agree with Elizabeth. By purchasing with the home you are saving the seller a lot of effort and headache. If I were in the seller's position and did not wish to put forth much effort selling each piece, I'd settle for 1/4 retail.