Keep shopping. I had mine done this spring at an authorized ACR repair facility (Marine equipment based). The cost was $80 + $5 return shipping. That works for me.
Craig

Hmm, I see that the cost of battery replacement for the ACR PLBs has gone up a lot since I bought my ACR PLB. Has anybody looked into the current best deal for this? Lowest I've found for a factory-authorized replacement is $125. That's extortion, but still a lot less than buying a new PLB of any make and model.