Yes, its better than the c26 IMO. I remember one selling for $700. If your friend's 504 is on mint condition, then its a fair price.
McIntosh Preamp Decision...C26 or C504
I've been using a C26 preamp for 30+ years. Now having minor problems. I don't know what aq C504 is YET, but I have the chance to buy one long distance from a friend. I don't have to pay for it unless I like it. He wants $750. for it. Is this a fair price? Is it an improvement over a C26? I would like more versatility. I would REALLY like it if it has balanced inputs. Any thoughts or opinions or advice?