Audio valuations

Without prejudice to its noble intent, this post is functionally elusive , rather useless IMO , for numerous reasons. The key one is the arbitrary and fluid pricepoint peg that is totally variable and dependent in lockstep with the economy.

Simply put:

-- in economic "good times", resale prices are comparatively "generous" and arguably inflated as buyers ride the "Good Times" wave;

-- conversely in economic "poor recessionary" downturns, resale FMV prices are dramatically reduced as buyers toss around nickels like they are manhole covers.

The best way to find the real price is start high, and slowly lower the price until it sells. THAT is the right price.
Economic conditions, and good or bad luck may also intervene.
I mean if the item has one (or a few) person(s) looking for it, the item can sell at a higher than normal price.
If no one is looking for it.. Then it may not sell at all!

I had a Audio Research SP-10mkII I put up for sale here.
(I also had a SP15 which I thought was far better sounding, so off with the SP-10)
I got it cheap, and listed it for $2,200 at 7AM. Within thirty minutes I had FIVE requests to buy it... by 7:30 AM CST.
The going price was $3,000.
I was satisfied, I had no need to chase the money.

Patients timing and compromise 

I always look at hifishark and ebay's completed sales before I buy or sell anything.

elf1, you have been lowballed.  The 6b goes between $1000 and $1100 normally.

Lots of 6 series ARC preamps sold, and an active used market.  Audiogon's Bluebook lists them all, and eBay sales, Audio Mart, and other sites tend to agree with the values posted there.

This series goes approximately as follows:  6, 6a - $900-950; 6b - $1100-1200; 6c a bit lower, and the all-tube 8 around $1300-1500.