I have 50+ listings with brandbucket. It's an awesome venues. I sell 20% of listed domain/year of listing. They are extraordinarily picky and they don't get easier with a great sales record. It's well worth the $10. Early on I would pick a greater than $100 logo designs and honestly didn't seem to make a difference.
I have to buy 6 domains to get 1 listed. I actually just launched my own site
www.nameperfection.com due to the unused inventory.
To be honest everybody with these sites is really picky. It'd be great if I could find someone who had a bunch of inventory and just combine sites who I'd take a 1/3rd or so at least and just put the rest down to taste. The plethora of sites is getting ridiculous.
I finally found a good logo person off odesk who's doing 2 an hour at 3$ an hour. I just figure the logo is a cost of doing business and don't play it up like it's adding huge value.
I get occasional sales off afternic and sedo but nothing compared to BB. Got the first sales of np last month.