I'm just going through and posting about people I've dealt with in the past, they all deserve it.
We've purchased used AP T-10 cages from 2kdime, and everything went smoothly! He was professional, courteous, and communicated with us through the whole process. The cages were in great shape, cleaned and ready to use.
I could go on, he is a great guy to deal with and I wouldn't hesitate to purchase from him again. In fact, I sometimes hope he's looking to get rid of some more cages or supplies! (Or some of those great animals he has)