I mostly change my own watch batteries, but it’s done infrequently enough that I’ve never had the need to have a cache of batteries so I go to the Radio Shack, Walmart or a drug store and pay 4 to 5 a battery. Lately a bunch of quartz watches in my family have exhausted their batteries so I checked online with Amazon and Battery Bob to get multiples. The prices at Battery Bob are good but on Amazon they are amazing. I can get 5 to 10 brand new brand name (Maxell, Energizer etc.) watch batteries shipped and delivered to my door for the price of 1 at Radio Shack.
I knew watch batteries had good gross profit, but I never imagined it was that much.