Xmas gift suggestions

Well, you could get him a good AC cord for his preamp... but a few hunnerd buck would buy a nice choice of music from one of the vinyl sellers, too.

Does he have a dust cover for the turntable? There are nice acryllic ones available that should fit in your price range, if he has a dust problem. Also, a record cleaning machine, if he has a good-sized record collection--that would be a great gift, I got my brother one years ago and he's still thanking me to this day. I hesitate to recommend tweaks because they are really a matter of personal taste. If he's thinking of getting into digital (you don't list one in his equipment), perhaps an inexpensive but decent CD or SACD player?