Since there are few reviews on this, I feel I should contribute, having tried the service myself. AuctionTeller wants to be like AuctionWagon, a complete consignment solution, and while they may provide this, they do it very unintuitively.
The interface is a bit confusing and offputting, and you can't really figure out how to do what you really want to do, like take a customer. Simply as a result of the confusing interface, I couldn't figure out how to take a customer's item and list an auction. But based on the listing features, I wasn't sure if I even wanted to do any listing with Auctionteller anyway.
AT looks like it offers all the solutions you need to be a consignment seller, but don't be taken in too quickly. It's not as easy or complete as you might think, and support is minimal. I did get a response from a tech, but he was unable to solve the problem.
Bottom line is AT isn't the worst solution. My review is not in depth because my experience with the service was not in depth. But it was enough to make me not want to use it. You can try it for free, so if you like it, then stick with it. But for now, doing a small number of listings, I'm actually better served with my own spreadsheets and filing systems, and taking full advantage of Auctiva's totally free services.