You shouldn't have to reason it. If you can afford it and pay all your other bills, then you should treat yourself to it. If it will make you happy and you don't have anything that you need to pay with the money, go ahead and do it.
I have the same issue with bags that high, but if I really want something, I'll do my darndest to get it.
ITA! If I like it and it makes me happy, I figure that's reason enough.