I'm not sure what getbig is hosted on and what the technical specification are, but having a very busy webpage myself with high tech specs demands I can tell you
given by the number of visitors and mostly guests (putting in consideration that you cannot compare a forum with a video page like mine) he would need at least a dedicated with capped bandwidth (I say at least 50mbps capped).
I agree with you Racspace is the Ferrari under web hosting very efficient very professional 100% up time great service and all - BUT extremely expensive.
He would at least needs something in the Enhanced One offer which comes at around $900 a month.
So what happens if your friend leaves Rackspace? And ron does not have a contract? Let me answer that for you, they will simply tell him to get lost and we either don't have a board anymore or Ron has to go back to a slower server.