I saw this exact same one along with the other 
DBZ sketches at Mandarake before.  They are 
expensive selling at over 80 bucks a piece.  
Yeah, and they're drawn on some notebook papers, 
so I suspected they're fan drawn based on the 
original pencil boards.  However, the staffs 
there kept saying the sketches are drawn by the 
creator, Akira Toriyama (yeah, right)... fake 
stuffs to me.