That's exactly the point. It has nothing to do with a monopoly - retail is all about cashflow. Walmart has 2.8% net margins, and do it with a maniacal focus on cost control and vendor management.

A manufacturer with a unique product can control pricing and manage demand. The business is the "vertical", they don't live or die with retail. Apple discounts through authorized third parties only. Rolex constrains supply, controls retail price & experience, and generates demand with the secondary market premium. People buy a watch for $15k because it's "worth" $20k. It's inferior as a tool compared to a watch that costs $50, and there's a whole spectrum of fancy watches that don't have the same cachet.

JC Penney doesn't have that. They're stuck with a warehouse full of low-margin pants and need cashflow, so they discount to get cash in, then jack the price up at different part of the demand cycle. Khakis that are $40 for back to school are $75 right now, and coupons are used to keep the cost conscious folks coming.