One of my concerns with our current phones, and with replacing the batteries (which, granted, we can carry battery packs) is that we (me and MR SK) both travel, and he will be in Japan in the fall for awhile (and presumably, I'll be there for a big chunk next summer). Being overseas and having a major problem with the phone would be a huge hassle.
So I tend to think I'd prefer to get a new phone (or at least a refurbished one) rather than pay for a new battery for these phones...
I dunno, I need to think about it more,but I think I want to decide what to do, and then do it, before the fall semester starts and I get busy again....