Friend is setting up a trip to go to amusement park and concert on same day. Friend asks if you want to go, and I say "Sure. I only care about the amusement park, but I'll do both. (because it's a 2 hour drive)". He says he'll order the concert tickets now, and we'll buy park tickets at the gate. He ordered the concert tickets. Turns out the park isn't even open that day. I'm not going 2 hours to a concert that I don't care about. Do I owe him money for buying the concert tickets, or do I make him eat it because of his poor planning that cut out the only reason I wanted to go in the first place.