How can i contact the seller of a character?

There is a character on warmane trade i want to buy but id like to negotioate with the seller about some unwanted items.

I added his character ingame however it has never been online during my own online hours.

Do i have a way of contacting the guy who owns the character/ finding out who his alt(or main) may be?

Can't log characters while they are on sale. Spamming global chat is like finding a needle in a haystack.

Only staff could help you, but I'm not sure if they can.

Try match history, in case they've played arenas with friends...