Jewel, huh? I dunno why I haven't noticed that but I don't shop there often enough. I was just told about that.Given that we're airplane folks, I'm surprised no one has brought up the ultimate in elastic pricing, the airline seat! Those can vary in cost from one minute to the next, depending on more factors than I can even consider! I've always found it rather Byzantine and don't particularly like it, but it isn't illegal! Heck, it would be legal for a gas station to charge a gas price based on how expensive your car is, how long it's been since you last filled up with them, what your average purchase is, and how much gas you have left in the tank! It just wouldn't be very practical!
Around here, we have a number of grocery stores that are tying fuel discounts to the amount you've spent on groceries using their loyalty cards. One will give you a penny off per gallon for every $10 you buy in groceries, up to something like $1.50 off per gallon, and the discounts are cumulative over time. They max it at 15 gallons, so their maximum cost would be $22.50, after you've spent $1500 on groceries. Their max cost is 1.5% of your grocery purchase.
Airline seats have time-limited value like theater or concert tickets. The value goes to zero after the plane leaves or the show starts. You can make a case that the value should vary during the time before. Hot tickets on Broadway are $1000 or more, but you can get some for half of list price the day of the show.
The reality is that time is the value. At any given minute they're saying "how much would you pay?" and consumers are answering by buying. Examples: The snowmobile in my garage is worth $600. We get 48" of snow and I'll take offers starting at $5,000. There may be a lot of interest in my rowboat during a flood. If you need to get to a business meeting you pay $1500 for one of the few seats left while the family next to you got seats 3 months ago for $149. It's not a scam. It's business, Michael.