Even if I hadn't got a nice layout sketch of 
Bender from Futurama in my cel book right this 
moment, the fact that I've seen sketches and 
whatnot from Futurama, Family Guy, recent Disney 
productions (dammit, don't cost so much!), and 
recent episodes of the Simpsons is enough to 
indicate to me that this "dealer"'s advice isn't 
worth a dime.  Some might be done all digitally--
I'm almost 100% positive that all the Adult Swim 
ones are, though they might have had a few stock 
poses drawn out and scanned in before shooting--
but there are still plenty of productions being 
made with honest-to-god paper and pencil.  

Now, whether you can find and then afford those 
drawings is a different question. But they're 
there. Oh yes.