Without sounding flippant, I'd say the best price is the lowest offer that a seller accepts. Lowest price for an 861 I've seen advertised on AGon is $4300. I have one for sale myself at a higher price. Depends on condition, age, feedback on seller, etc. My recommendation is to find someone who has the unit you want (830, 831, 860, 860x, 861, 27ix, etc.) and make them an offer. Only thing they can do is say no.
RE: Steve's comments. I currently own, and am selling both, the 861 and the Accuphase 75V. Mileage varies, but I would never characterize the 861 as "sterile and uninvolivng". I have heard this rig in many setups, and it can sound fabulous. Steve is correct that Accuphase has more "euphonincs" and sounds a little closer to analog, but the Wadia has a sense of quiet and background that can be spooky. Both are reference players, which cater to a different type of sound.
Best of luck in your search. Wadia makes great products.
TRH