Which Olympics would be relatively cheaper to attend? London or Sochi?

I would like to either go to London in 2012 to see the Men's Gymnastics, only if Paul Hamm makes the U.S. Team, or to Sochi in 2014 to see Men's Halfpipe, to see Shaun White. If I went to Sochi, I would also like to maybe catch a hockey game between the U.S. and Canada. If I go to London I would also maybe like to catch a swimming event to see Michael Phelps. Which would be relatively cheaper when including plane tickets, hotel costs, food, transportation, and event prices?