Sorry dude. You will not be getting a SERO from bestbuy. These plans are legacy, and arent being offered anymore by anyone (not even sprint). IF you are wanting SERO, check the bargain trader threads, there are usually some that pop up on there every now and then. I bought 2 of my SERO accounts from there nd had great success.
You may want to read up on SERO and EPRP here:
http://wiki.howardforums.com/index.php/SPRINT_SERO
Hope that helps!