<snip>I don't have enough information to know if changing the battery is a straight forward process for the technically inclined or if it is a matter of revenue generation for the PLB company. Or perhaps since it is a life saving device not letting consumers toy with battery replacement is a wise decision.
That looks like a proprietary battery pack custom made for ACR. You can find people that will replicate such things with the shrink wrap and all, but there's going to be some soldering involved. I seriously doubt you will find one ready made and ACR for sure won't sell it to you.
That said, I would do something like this for the rechargeable battery pack for my cordless drill. I would not do it for something involving life critical communications. I want to know the lithium batteries are fresh, I want some QC involved, and I would like it tested before its handed back to me. If it were an Ipod a cell phone with a permanent battery, the market would offer solutions cheaper than the manufacturer. But the life critical nature of this device and the litigation potential will likely leave the manufacturers as the only source.