Oh yeah, the CR123 is very expensive and hard to find, which is weird because it is used in a lot of cameras, flashes, NVGs, you name it.....
Here they are:
https://www.batterymart.com/p-hitech-cr123-lithium-photo-battery.html?utm_term=CR123-BULK&utm_source=GoogleBase&utm_medium=CPC&gclid=CL37m7TrzLUCFcdxQgodQ1IAyg
Wow 500 for $0.89 each... very expensive and hard to find.