It's the John-at-the-grocery-store absurdity.
(Comic Strip 7090, Original Publication Date, 3 August 1981)
Throw-away Panel 1: We find John at the grocery store with the kids thought-bubbling "Holy Cow!!!!" as he takes a can off a shelf.
Throw-away Panel 2: He then dates this horribly by saying that the last time he went shopping for soup, it only cost a quarter. Good thing that most papers (and ucomics.com) will not show this; it helps to keep the confused letters to Coffee Talk down.
Panel 1: As he puts a box in his cart, he thought-bubbles about how he doesn't believe the prices these day.
Panel 2: Before he can launch into an ignorant rant about how in his day, things cost what they should, a woman in her early fifties calls his name.
Panel 3: He smiles and says "Helen Binks! I haven't seen you in ages!"
Panel 4: Mike rolls his eyes in boredom as the grown-up's silhouettes trade small talk.
Panel 5: He then says that Elly will kill him if he doesn't get her address; this, of course, is because the Pattersons write enough unsolicited mail to qualify for the bulk rate.
Panel 6: She searches through purse, exclaims "Oh, dear" and very awkwardly sets up the punchline by asking him for a worthless piece of paper to write on.
Panel 7: It takes John two panels to say "Err, sure....."
Panel 8: "....here's a buck."
Summary: It's bad enough that Lynn is making a very awkward complaint about inflation without it being as dated as this; all she seems to have done to "update" it is to tweak the coloring like a child playing with a shiny new toy and chop off the throw-away panels. It would have been better to keep the coloring the same and update the prices a little so as to convince people that this is actually the present day.