H.P. Lovecraft books sell every day.
Clive Barker is Liverpudlian, but lives in Beverly Hills, California.
Anne Rice, obviously.
Peter Straub.
Owen King bears mentioning, as well.
Dean Koontz, Stephen King, Robert McCammon’s earlier stuff, Peter Straub and John Saul, Anne Rice…there are a few others like Poe or Lovecraft, but they are no longer writing for obvious reasons. I guess if you were younger R.L. Stein would fit the list.
As far as I’m concerned H.P. Lovecraft is practically untouchable, even with his xenophobia and racism. Though if by “sells books even today” you mean are they still writing and publishing then Lovecraft hasn’t really done anything in awhile.