Yes, Energizer Advanced Lithium (EAL) are pretty expensive. And while just now looking for a price, I realize that EAL is last weeks technology. Now we have Energizer ULTIMATE Lithium (EUL) which are claiming a 20 year shelf life for AA cells, Amazon has them in a 4 pack for $5.89 which is $1.47 each.
In response to your previous post, I would suggest that you try a Manker A01, which according to this thread was pushing 100 hours on moonlight from a AAA dollar store battery.
I have several of these, in use in places from Keychain lights for my kids to zipper pulls on my tents. We might be able to trade if you are still interested.
[edit to add]
More than a few people have suggested that embiggerizing the A01 to a AA battery and changing nothing else would be a great idea. I don’t know what is keeping Manker from doing so.