F.O.A.D. wrote:
...the battery in my diver's watch died, so I took it to the watch guy
I trust and he told me I'd have to send it off because of the way it
was sealed, the special gaskets, and some kind of vacuum tool needed
to reseal it.

Sheesh.

So I sent it off to the manufacturer's repair shop in Rhode Island,
and the estimate came back for close to $100. To replace a watch
battery. That probably wholesaled for $3.00. The actual price turned
out to be $96 and it took a month.

http://tinyurl.com/ma8t2ju
My Tag Heuer battery was $15 with a pressure test. I would never pay
1/2 the price of an old watch for a battery replacement.