When calculating what was cheaper -- repair or replace my old razor -- I forgot to take into account compatibility of accessories like the sideburn trimmer and shower hanging cord. The trimmer for the old razor doesn't fit the new one, and I didn't need a hanging cord at all because the hole in the razor's base was suitable, while the new one doesn't have a similar holding point. Factoring the costs of those things into account, it looks like it now would have been a little cheaper to pay for the new batteries than to buy a new razor. That assumes the razor's motor was not going to fail as well, which was a strong possibility, the technician said. I still wish I hadn't given them the old razor for disposal. If Lisa had somehow been able to install a new battery, I could have used it exclusively as a sideburn trimmer, which would have extended its motor lifetime substantially. Darn it.