Well, it looks like we sold Amazon out of the Black Kandles, although you can still order the White ones. I don't expect these to last much longer, either, so grab them while they are there.
In the meantime, though, I searched thru the listings for the CR2032 batteries that these use. I also have several other items that use this same battery, so I thought I might stock up on a few extras. There are a number of generic bargains, such as SE CR2032 Lithium Battery, Package of 5 (5 Packs) ($6.39) or Powertron Lithium CR2032 (Pack of 25) ($8.19). The biggest problem with these generics, according to the reviews, seems to be a small number that show up already drained and that sometimes they are just loose in bags, rather than in blister packs. On the other hand, at $1.28 to to $1.69 a 5-pack, having a few bad ones in the bunch is still cheaper than the typical prices in retail stores.
If you want to stay with the name brands, the most expensive seems to be Energizer, which even in a 100 pack runs $44.49. But there are some good deals on Maxell, it seems, with a Package of 5 at $2.49 or a box of 100 for $32.05 (both with free shipping), which works out to about $1.60 a five-pack.
Update: Note that these battery prices seem to change quickly and vary by seller; if one sells out, you may get a price from a different vendor, even on the same ASIN/part number.
Update #2: I'll put this note on both posts about the Kandle. The 60% off on the second Kandle when buying two is now gone (as well as the Black Kandles being sold out). The promotion code (KANDLELT) is still working for $12.50 off when you buy two or more, so they are now effectively 1/2 price (2/$25, 3/$37.50, 4/$50 etc). Still a good deal, but nothing like the wonderful deal yesterday (when literally thousands were sold, if the response from other blog's readers were anything like the response to my blog posts).