Thanks for your input and confirming my suspicion that CR2032 batteries would not be a long term economically viable solution for insomniac users. I rather stick with my single rechargeable AAA battery for now and have already started saving for a lighted e-reader (sigh: my NST is only 9-month old. I guess it's how the life of the digital world is supposed to be.).
I heard that Sony will launch their Sony PRS-T2 soon and also that Amazon too would launch a lighted Kindle. Hopefully, one of these will use something like a flex lighting film
instead of a top row LEDs like in the Nook Glow so that the illumination could be completely uniform and the surface less fragile.