Because of eBay's rules against listing teacher's editions, I've chosen to list a Spanish curriculum at ThisLittlePiggyStaysHome.com, a homeschool auction site set up specifically so that homeschoolers can sell their curricula complete with teacher's editions.
I used this service a couple of years ago and was extremely satisfied with the results there. Auctions went well and there are no listing fees. Only final value fees. It's easy to list auctions there and takes almost no time at all to get one up and running.
Because I have so many teacher's editions to go along with the sets of books I have to offer, the lion's share of my auctions will be at TLPSH, with only a few things over at eBay. Anytime you're looking for my auctions here, you can just do a search for my user name and they'll all come up: homeschoolzoobooks.