WOW, 1988 was one heck of a busy year for you! Saving 1988 dated bills sounds like a great way to commemorate it. Do you save coins of that year also?
No coins unless they are in outstanding condition. I do have a few nickels and quarters from that year but only because when I got them in my change, they are in condition like right out of the roll from the mint. My primary objective however is the paper currency from that year though. It's not really cost me anything to do this. I've got a stack of roughly 40 $1.00 bills, a few $5's, 10's and $20's only. No $50's or $100.00's. With those two large bills, I'd be tying up too much money in something that has just a personal novelty / trivia meaning to me.