So far the cheapest I've found it is @ $3.21/ft for a 25ft roll through 
www.ryderfleetproducts.com 

this is the link (if it works) 
<http://www.ryderfleetproducts.com/ryder/af/ryder/core/content/product/srm/key/U29%2080089/pn/Fuel-Hose-Injector-Roll-5-16/erm/productDetail.do>

Dan in NY
www.EmpireVWcamping.org 

Date:    Sun, 13 Nov 2011 18:57:25 -0500
From:    craig cowan <phishman068@GMAIL.COM>
Subject: Fuel Injection rated hose

I'm looking to buy a spool of hose to replace fuel lines in several
vanagons.
I know I need 12 feet per bus and 5/16'' hose is suggested and i've used it
before (I know, 7mm is better, but good luck finding any).

What Pressure rating do I need?
50psi seems to be a common rating and that 'seems' to me to be sufficient
but this is why i'm asking.
Does anyone know where I can get a spool of good fuel line or at least what
pressure I need to deal with?

Thanks!

-Craig