I have about 150 first class stamps that I have purchased last year. The mailing that I was going to use them for never happened so I am using them slowly.
It turns out that the USPS has just raised the postage rates, so I went and asked them about my stamps. The postal clerk had to examine my stamps, compare them to some kind of catalog and ask her boss (to be on the safe side.) And then she declared that the stamps were vintage of 2007 and that I will have to add a 1 cent stamp for fist class mailings.
So, let us say that my wife buys some more stamps and the rates go up again (UNLIKELY EVENT ???!!)
We will have two kinds of first class stamps (they usually feature The US flag) that we will have to make sure we do not mix them up otherwise we might lose a lot more money (for instance: bill payments will be returned for insufficient postage and generate fines and/or additional interest.) Then again, she may not buy more stamps. It is still annoying that you cannot look at a stamp and know the value of it; it resembles old time colonial practices when newly conquered territories had temporary stamps.
It used to be convenient to buy rolls of 100 stamps in order not to have to wait in line every time I had some mail.
But now, I might have to wait in line just to find out if my stamps are still good. Just how difficult can it be to print the price on the stamps? I say it might take all of one hour and 5 minutes (if we allow 4 minutes to turn on a PC and a one hour lunch.)
... AND SO, 1ST CLASS IS DEFINITELY LAST!!