Bringatrailer is NOT the site to shop on if you want a bargain.
The clientele - the real buyers - not the surfers and commenters,
are largely fairly well-heeled. Some of them have annual disposable
incomes in the millions of dollars. If they really want something, they
cheerfully pay the freight.
For the seller, the site is terrific. One gets a targeted audience of knowledgeable
gearheads who have the money to pay for what they want. No tire kickers, time-wasters,
scammers, etc.. The customers appreciate maintenance records, attention to detail,
and honestly represented merchandise. BS artists are called out pretty quickly in the
comments section. It really is a seller's dream if they accept your vehicle.
I spent YEARS trying to get a fair price for my nearly perfect GB500. I got a
very fair price on the very first try at BAT. Yep - it cost me $99, but it was money
that was VERY well spent.
That said, some of these bidders can really skew the market. One GB500 went for
$16K! Yes, it was mint, low mileage, and had some rare aftermarket goodies, but
it went for WAY more than it should have. Of course, this sometimes happens at
auctions when there is a bidding frenzy!

On the other hand, looking at
average sale prices over time on BAT, it seems that in many cases the average comes
fairly close to the actual market value. Not always, to be sure - and in a lot of cases
the sample size is too small to draw any conclusions. (Exotica excluded.....some
of the one-offs are beautiful - and EXPENSIVE!!!)
-Stretch