Well we were talking about the increased cost of car batteries... Unfortunately I just had to pay it.
Got into the Flex with the kids to take them to school this morning--wouldn't start. Thankfully we hopped in the Jeep and got them there and on time, perhaps a little colder than planned, but overall fine.
Battery was >5 years old and out of warranty, tested as poor health, and so $208 later I've got a brand new one.
Yay.