I haven't been in a while, but quite a few spots in B-town have closed down over the years. Still, first place I always head to is Rik's Records in Portslade. Always some cool sh*t in there, and the prices are often pretty reasonable.
ive been lookin in the yellow pages and two shops ive been to so far are riks disks in lewes and the wax factor in bton. both reli gd shops, wax factor had about 5/6 crates of £1.99 sales so i copped some of them