I bought a 522 from eBay on Sunday that I received yesterday, and had it activated by emailing my request to
ceo@dishnetwork.com, as instructed here. Before I purchased it, I had the seller give me the receiver (R00...) and smartcard (S00...) numbers, and I called the regular Dish help number and confirmed that the receiver had never been activated.
Before I found this forum, I sent an email to the regular help address, and SIX

days later got a response that they would not activate a 522 purchased from eBay. But after reading the posts here, I knew that was not really the case.
I sent an email with the receiver info and all my subscriber info to the ceo address last night around 10:30pm MST. Amazingly, I got an email response within 10 minutes, asking if I wanted to add the 522 to my account or replace one of my existing boxes. :shocked I replied that I wanted to retire my 301 and keep my 510, and within another 10 minutes or so, I got a reply that I was all setup.

The regular CSRs need to take note - this is the way to do business and keep happy customers.
Thanks to the info I found on this site, everything went more smoothly than I could have imagined. Now I'll see if my 522 suffers from the bugs everyone else is reporting, but at least I know what to expect. (And despite the glitches, it's still very cool technology.)
BTW - I paid $201 delivered to my door, for a brand new, factory sealed unit. Dish is ridiculous to think I would pay them $149 up front and then $5/mo forever and never own the equipment.