How much should it cost to change the battery in my Tag Heuer Aquaracer waterproof watch?

That depends on where you are and on if a professional watchmaker is doing it (so the job is done right) or if you are taking it to a watch breaker at the mall or local jeweler.

A watchmaker will not only change the battery but will make sure the watch is resealed again which could require new gaskets. A watch breaker doesn't care about such things and will charge almost nothing but your watch will not be guaranteed to be water resistant from one of those people.

Water resistance is important. Everyone perspires and that moisture will get inside a watch if it is not sealed. It may not seem like a lot of moisture to you but honestly, the parts inside a watch cannot stand moisture. They corrode and rust within a few days even with the smallest amount of moisture. Once rust starts it cannot be stopped by drying the watch out. The parts with rust damage normally have to be replaced.

Now on a $10 watch no one will care about water resistance or for that matter replacing the battery most times. But on an expensive watch such as yours this is important because having to replace the parts of the movement is expensive and so you can expect to pay more for a professional battery change.

Hope this helps,

Ken
Yellowstone Watch, Inc
www.yellowstonewatch.com