Let’s keep it simple. Does any store allow goods to be sold without a markup for them to make a profit? When I walk into Walmart, how many of the items have a price labeled from the factory? Has any retailer of digital goods ever sold at cost? Does Epic charge a markup for their digital goods or do they sell at cost? Can I buy virtual goods for use in Fortnite and avoid the “Epic tax”?

No one said there is no markup. MSRP is explicitly not "at cost" or even wholesale. That is the actual point. MSRP is constant at all retailers though.

You really think that all retailers sell the same goods at the same price? Have you ever looked at the price of snacks at a movie theatre and compared the price anywhere else? Heck even at the grocery store a 20 ounce soda sold on the aisle is cheaper than the same soda sold at the checkout line refrigerated.

Are cars all sold at the same price everywhere? TVs? Computers?