Every once in a while I mail a letter without Nancy's help. In her box of stamps, she has every denomination from 1 cent to 37 cents, and a number of rolls of stamps that say 1st Class. How am I supposed to know how much they are worth? When I mailed my letter I used a 1st class and a 2 center but later Nancy said she just bought the roll of 1st class for 39 cents each. I can afford the 2 cents but it pisses me off to give the gov any extra $ especially at this time of year. Q: do I need to take the stamps to the PO to see what all the various 1st Class are worth?