Unfortunatly there pretty expensive, I mis-quoted 
the model I've got at my studio, its the epson GT-
30000 and its around $3500.  This is a 
proffesional scanner, and a total lifetime 
investment, I definatly wouldn't have one if I 
didn't need it for business everyday.   Epson 
makes 3 13x17 flatbed scanners they range from 
$2400 - $3500. However you can get that quality 
in a smaller 9X12 for much,much cheaper.  I 
personally would go for an Epson though.  Even 
there consumer end scanners are known for great 
quality.  Here is a page that shows the range 
they carry from proffesional to home use....

http://www.superwarehouse.com/cb2.cfm?
Epson_scanners&b=91&c=51&CMP=KA18401

Hope this helps!