my mom would have been mentally calculating how many loaves of bread and pounds of sliced meat she could buy for that amount b/c 'we have perfectly good lettuce, pickles, tomatos, onions, mayo and mustard at home'

thinking back now-with the exception of being on vacation and going to a coffee shop where I might choose a club sandwich for a meal I can't ever recall eating a purchased prepared sandwich until I was in college (we did not have realy any independant delis and the chains didn't hit our region until the very late 70's/early 80's so that may have made a difference).