https://blog.hackster.io/yoga-mat-size-pressure-sensor-matrix-uses-lattepanda-and-velostat-to-save-money-49ee86950e5a

Scale is, of course, one of the largest contributing factors when it comes to the overall cost of a project. A single LED, for example, costs just pennies. But if your project requires thousands of them, the cost of the BOM quickly becomes overwhelming.