Why did he all of a sudden do this?

Well bf my got NHL season tix, and he was so excited. The thing that got me upset was how he went off saying within a year he would propose because he didn't have enough for a ring yet. I told him that instead of getting these tickets which are a 3 year commitment at $100 a month, he could have paid off his bills, save up for a down payment, etc. So, we had a huge fight, and I just started crying because I was so hurt. He thought of himself, not us. So the next day he tells me that he thought of a plan that would make him able to get my ring maybe before this December. So I am wondering why couldn't he have thought of this sooner, why did I have to point it out to him?