I just had the master seal on the power steering pump of my '87 Maxima
go bad.  Originally I went to a dealer who quoted me a little over
$600 for a new pump and with labor.  However, I had a friend of a
friend who knew a mechanic.  He was able to pick up a refurbished pump
from Napa for $175 and installation for 1 hour was $30 because of the
friend connections.

I know this car has also had its entire power steering rack replaced
in the past.  My parents took care of that so, I'm not sure what the
deal was.

Anyway, my recommendation is to ask friends or coworkers about
mechanics they know so you can find a deal.  The mechanic who serviced
my car normally worked on Chevys and didn't even have to look at a
technical manual to figure out how to replace it.  It seems like it's
a common sence removal and installation.  Good luck!