I had it, and dropped it after a month.
I have been an "Insider" for a few years, having first joined during one of Audiogon's 50% off promotions. I'm sure there must be other reasons, but the main reason I have maintained my membership is for the Audiogon Bluebook. I use it as a second opinion when evaluating the prices of used (especially vintage) equipment. I refer to it when perusing other websites as well.
It’s hard to generalize about whether the quotes are "accurate" or not, but it helps me to recognize a price from a seller who is hoping to snag some newbie by pricing an obscure piece of gear at a ridiculous premium. The best examples for me are the prices of receivers from the 60’s and 70’s. Just having a nice wood cabinet doesn’t justify a multi-thousand dollar price.