eBay @ £399
I bought one from this guy, I too were concerned re the change of ID however changing your ID doesn't negate your feedback profile it follows you. I did contact a previous buyer who was pleased with his service.
Mine arrived yesterday by Special delivery, brand new as stated and it took a whole 3 minutes to unlock it using the software from this site.
Just having fun learning to use it now.
O2 may have commisioned a great product but as phone providers they suck, spending most of my time getting their s#*t of the XDA II.