Lithograph mainly is a printed matter which it is 
produced in limited amount.  Let's say an artist 
draw a beautiful illustration, he printed 100 
copies on very high quality paper, sign his name, 
put a number, and framed it.  Then he sells it 
for $200 each in 100 limited copies.  Lithograph 
priced very differently, depending on the artists 
and publishers, they can start at any price that 
they want to, as long as there is demand.

To me, I don't like lithograph because it's 
pretty much a poster, except it's in limited 
edition and printed in high quality paper, signed 
and numbered by the artist.  Other than that, why 
pay $200 for a lithograph when I can pay $10 for 
a poster.  That's only what I think, there're 
many lithograph collectors who're willing to pay 
for them.