The ProTools 11 upgrade from ProTools 10 activation card at Guitar Center is $299.00.
ProTools 10 is 32bit and all the plugins are RTAS so they can only be used IN ProTools - the plugins are not VST and cannot be used in other DAW programs.
If you wanted ProTools 11 64bit with the new AAX 64 bit plugins this is a cheaper way to get to that. Pay $99 and register then upgrade for $299 and total cost would be $398.00. This assumes you already have a iLok2 usb dongle as ProTools still requires iLok 2.
Protools 11 new full goes for $575.98 at MF. Save $177.98.
I paid $599.00 on one of the specials and got Avid Eleven Rack guitar effects, iLok 2, ProTools 10 & 11. I don't see that deal being offered anywhere anymore. MF has this bundle but it's $899.00.