Garmin 530 WAAS upgrade - what's involved?

We recently put a 530 in one of our planes. Garmin says the upgrade to
WAAS is only going to be $1500. Sure, that's what they charge for the
guts, but what is this likely to run to once the shop starts adding their
labour costs, etc. Is another field approval needed, or what sort of
paper work?

--
Paul Tomblin http://blog.xcski.com/
Sign on door of computing lecturer: "If your project is 90% right,
I have to give you a distinction, your employer will fire you."
-- Zebee