No heaving duty printing, mostly "how to guides" an occasional
picture.
I can't find them (takes 2) for under $20.00 a piece online, and that
doesn't include shipping.
Yes, that's how they make their $. You either pay around
that much or find some generics and test them till you find
one that works acceptibly (though Lexmark was one of the
companies a bit more aggressive about preventing generics
use and pursuing those who made generics).
As another poster already mentioned, in the long run it'll
be cheaper to get a B&W laser, if you can accept B&W
printing. Might even be cheaper to buy a color laser if you
did enough volume to offset the high initial and replacement
toner cartridge costs (hundreds of dollars to replace all 4
cartridges, actually one business class color laser I have
costs about $1000 to replace all 4), and though color laser
print quality has increased in the past few years it is
still less photorealistic than a good inkjet.