First Class postage was 25 cents for the first ounce beginning in April 3 1988. This rate was valid through February 1991. At that point it went up to 29 cents. I have at least 80 of the 25 cent stamps, and 65 of the 29 denomination. There are a few of the other stamps of the past - 32 cents, 33 cents, 37 cents - but not in those large quantities.
This is one of the ones I have:

For this Christmas card season, I'm using 2 of the 22 cent stamps, hoping to use most of them up.
Someone is going to say I should save these old stamps for their collectible value. Like Beanie Babies, this is not going to happen in our lifetime, so might as well use them up.
and mail parcels all without standing in line.