George spends $2,000 for a plane ticket to Vancouver and gives up $500 because he has to take time off work. He spends $1,500 on his hotel room. In Vancouver, George is trying to decide whether he should spend $1,000 to take a side trip to go snowboarding in Whistler or just snooze in the hotel. Going to Whistler would be a smart decision as long as his benefits from the side trip are at least