Hard Bargain To Change A Watch Battery

My watch battery died a couple of weeks ago. I hadn't had enough time to take it and have the battery replaced until last Saturday afternoon just before 4:30. Most shops closed at five but this one just happened to have a 4:30 finish scheduled.

I asked the lady in the shop how much to replace the battery. She said it would be $34.95 and I, somewhat shocked, said that it cost $25 only two years ago. "It was $28.95 in January," she responded. Then she kept going on about the need for a pressure test, the watch is water resistant to 100m, but I wasn't interested in paying $75 (plus inflation from eight years ago) for that, which didn't put her in a good mood. I've had no issues with water so the seal must be in good nick. Not having a great deal of choice I accepted her offer.

She set to work and seemed to be struggling. I offered to go shopping for a few minutes and return but she wanted me to wait. Obviously wanting to make a fast getaway. When it came time to set the watch she was bamboozled. "Do you know how to set this watch?" she asked.
"Yes."
"I'll only charge you $28.95 then."

Six dollars for less than six minutes work? So, I got my bargain but had to do some of the work myself. And the watch is slightly more difficult than a video recorder to set so I did myself a favour. Gee, what's it going to cost in two to three years time when the battery needs to be replaced again?