Suggestion: Blocked People
You can set the nicknames from your contact list of both friends and blocked people, by right-clicking their name in the list.
Regarding gold sellers – it’s safe to delete them off your ignore list once they go offline, because that offline is usually the permanent ban they get, and they never come back. Obviously, if you want to play it safe, keep them blocked, but I delete them after a short while just to keep the list one page long (if I can).
Blood & Merlot [Wine]
I once got messaged by a gold seller after coming back 5 months later. :o I guess he waited 5 months for me? When I came back I was in the guild hall.