If you have a stockpile of your supplies you'll notice that you can't replenish them long before actually running out and you can therefore increase the price o

If you have a stockpile of your supplies you'll notice that you can't replenish them long before actually running out and you can therefore increase the price of your product to extract the highest amount from whatever limited volume that you can still produce. Except of course when you are working off an order backlog, but then emergency procurement in an empty market will be even more ruinous.