I too an a textbook author and I really have to disagree with you about electronic distribution being "the answer". Printing is minor component of the cost of a textbook; it's a combination of very low sales (compared with fiction) and very high production costs which make them expensive. In the example you mention above, the "specialised equipment" to produce a technical illustration would still have been required whether that picture ends up on paper or in an electronic document.
Electronic distribution would knock a few $ or perhaps 10s of $ off prices. You're never going to get $5 organic chemistry textbooks.