Goal: How to save money on small electronics batteries using an A 23, 12 V battery from Walmart.

Which of the following methods is more reasonable for accomplishing this goal?
Buy A 23n 12 V Energizer batteries from Walmart or similar stores. Use a screw driver to remove the wrapping around the battery. Some of them have the smaller cells that can be used in small electronics, that cost up to 3 times as much.