No i haven't signed up either, I had bought quite a few MTH and Lionel steam engines from them on eBay over a 5 year period, then I tried one of TRAINZ "other" NON-EBAY auctions about 2 to 3 years ago. Had a horrible experience... the auction didn't end at it's posted time, my highest bid wasn't honored..
After writing in three times to complain, I got one ridiculous explanation about insufficient number of bidders (no reserve auction ??) and never got a response at all to the other two emails. I have never bought another item from them, and I doubt I'll ever spend another dollar there ! Good luck