You would, based on what you write, seem to have a reasonable chance of winning in small claims court. You would sue on two grounds:1) Breach of contract--of the (presumably) oral agreement that you would purchase the tickets and he/she would pay.2) Promissory estoppel--you reasonably took an action to your detriment (buying nonrefundable tickets) based on the other party's representation, or promise, that he/she would pay, when the other party either knew or should have known you'd have to do this.