Two questions:

1) Does anybody familiar with the metro Washington DC area know what a reasonable price would be for a mechanic to install a P/S pump on a '72 280SE 4.5?

I already purchased the pump and I just need to have it installed. A couple of places I called refused to install a part that I puchased myself. I found one place willing to install it, but they said that it would probably cost round $650. Does that sound about right? It seems a bit high to me.

2) How much, at all, is it okay to drive with a failing steering pump? I've only driven it once or twice since the problem was diagnosed, and the steering seems to work fine, just makes a moaning sound when turning a sharp corner. Is driving a few miles to the store a couple of times a week fine - or should I not drive it all?

Thanks.