So far I've received a quote of $150 plus shipping to change the battery, replace the gasket and pressure test it. That would be the thorough approach advised by ACR's attorneys to prevent spurious lawsuits.

But really, buying a new unit because the batteries are expired? This bothers me.

I found a YouTube video of a guy changing the batteries. It takes a little soldering (which I'm completely comfortable doing) but wouldn't pressure test afterwards. Considering I don't go kayaking or do really rugged stuff I'm considering doing the swap myself.