Wendy's plots new 'Uber surge-style' menu where prices jump up and down in line with demand - so when will be the cheapest (and costliest) time to eat?

Stupid way to market it.

You have to make people think they're getting a deal. Tell them you have a discount if they come in during off peak hours. Then slowly raise the price the rest of the day until the "discount" price is the old normal price.

That will mean it will be able to change prices in real time and at little to no expense

or just do what some of these restaurants do and don't have the price anywhere. It's not until you get to the checkout that you know how much it all cost.