Panel 1: As Elly holds up her prize, she smugly tells Annie, who's checking out the Grubberware, "Look at that! I came here looking for an electric can opener and I've saved twenty dollars buying an old-fashioned one."
Panel 2: De-aged Lizzie is sticking her tongue out in embarrassment because even she knows that that isn't much of an accomplishment; that, or she's reacting to Lecturing Moron Elly angrily declaring that she's just done her bit to curb unnecessary spending.
Panel 3: When she gets to the counter, the cashier tells her "Okay, lady; the pliers, tape, casserole, scissors and can opener come to $143.90." Her reaction is to be gobsmacked. (As am I; the price used to be 43.90 and shouldn't have gone up THAT much.)
Summary: What we see here is the Lynn model of inflation: stick a 1 in front of the price and hope no one realizes that prices haven't climbed THAT much. A smarter person would have changed the 4 into 7, 8 or 9. Also, Elly is feeling bad about something she should feel good about: stocking up on things she needs.
ETA: Lynn has changed the Seasonal banner again.