> For research papers... maybe 50 pages including technical graphics? With a monochrome laser printer, we'll give a very high estimate of $0.10 per page, or $5 per paper. That's still 220 papers to break even

Okay, so, yes, its cheaper to print paper than to carry a letter-sized, write-on-it, ereader.

OTOH, its a lot more convenient to carry one ereader if you have a lot of stuff to view than it is to carry a stack of books/research papers/etc.