Uh-huh... And
here's a <5mW bluray for
only $800... And
here's a 60mW one for a mere $2000.
If you want to buy a single 100mW diode it'll cost you
$1125... If you're random joe laser hacker, yes, maybe it'll cost you less than fifty bucks to make a laser yourself, but that's only thanks to huge buyers like sony investing in the technology, coupled with the internet community and forums like this, that you're able to find surplus parts that were bought in quantities of millions for a dollar apiece.
Some company trying to start up a laser business can't be relying on salvaged sleds from broken consumer waste, they can't be buying rkcstr or lavadrives, they need to contact the manufacturer for laser diodes and research and design their own drivers.. There's a huge expense in manufacturing that hobbyists don't have to deal with. Of course you're going to be able to build it cheaper if you do it yourself, but buying a commercial product is something completely different.
[edit]heh.. "surplus" gets filtered by the forum software as "spammer"... I'm glad I re-read that.[/edit]