You’re right. This is just evidence of a modern well-run supply chain.

Amazon does this better than anyone, and you’ll commonly find products available in different colors with each having a slightly different price. These prices change dynamically based on trends like historic and forecasted demand, current on hand quantities, and many other factors.

Edit to add: Some more advanced brick and mortar stores (see B&H Photo in NYC) use electronic price displays in the shelving to allow them to change prices more dynamically and frequently without having to incur the labor costs of restickering and retagging product.