Maybe I'm the only one, and if so that's fine, but I think a 1% transaction fee is entirely reasonable. Before I gravitated to Head-Fi, I spent a lot of time at Audiogon (not to mention money) and always enjoyed the interaction there.
But more to the point, the mere fact that Audiogon existed in those days ('01 and '02) made it possible for me to: 1) learn about all sorts of gear that I may not have otherwise stumbled across in a lifetime, and 2) get amazing deals in the used market without having to physically stomp all around the US to do so.
In that sense, Audiogon was most definitely the catalyst that got me back into high end audio. It allowed me to become a much more informed consumer and to find great deals from highly reliable members (in those days anyway). Audiogon "saved" me thousands upon thousands of dollars, or looked at alternatively, it allowed me to build much better systems on the same budget (as compared to brick and mortar shopping).
In fact, I remember being totally blown away by this! With Audiogon, I could find the best deal in the country on a used Velodyne HGS-15 sub, or a pair of Martin Logan Aerius speakers, and end up with a pair of mint speakers and a mint sub for less than what either of them would have cost at Sound Advice!
Maybe people take these things for granted now-a-days, but I sure don't. Places like Audiocircle and the AVSforum don't even come close to comparing to Audiogon, either in terms of the robustness of their marketplaces or in terms of the knowledge base and helpfulness of their membership (when it comes to high end audio).
But then again, I did about 150 transactions at Audiogon, and still visit their site almost daily even though I'm not in the market for anything. Perhaps others have not benefitted from their site as much as I have, which I can certainly understand - but paying $100 on a $10,000 deal that would have otherwise cost me $20,000 doesn't seem too bad. I'd imagine that many sellers will be able to pass off these transaction fees to buyers just as they sometimes do with PayPal fees. Alternatively, they can simply price their items in such a way that they will net the amount they were hoping to receive. If their item doesn't sell, blame the economy for the 50% decline in value, rather than Audiogon for the 1% fee.