I always find it funny when people complain about battery costs. A £3-4 battery (that's what a 2CR5 costs at most) will last you 20 rolls of film yet it costs less than 1 roll of film and that's just the film purchase price, I'm not even going to dev/scan/print costs.
As for weight...last time I checked a 2CR5 is a bit shorter and fatter than a roll of film and a lot smaller/lighter than 4 or 8 AAs, let alone some power drive booster needed to use those AAs.
Just to clarify, the 8 AA batteries I use are specifically for
around 6-8 hours of bulb exposure for star trails; often, not once or twice a year;
occasionally letting rip at 10fps ( that
is exciting: a roll gone in 3.4 seconds... )
Much better cold weather performance than 2CR5; and
the EOS1N doesn't necessarily need the power drive booster: it is
optional (it does improve handling). Take it off and ... fit a 2CR5, which it will use very miserly.