You say they are cheap.. and yet....
http://www.thinkgeek.com/gadgets/lights/896a/
This blue laser pen uses the same violet laser technology both Blu-ray and HD DVD use. And yet this laser pen is $900! The
green ones, which are brighter than red but not as bright as blue, are still around $100+. Red lasers are a dime a dozen, usually only $10 for a red laser pen.
Granted they are not paying $900 for a blu-laser in a blu-ray player, but it gives you an idea of how much more these cost then the red laser that DVDs use... i wonder why green got skipped over completely.