He's the only GHB vendor I trust, and I only ever saw him on Agora. Of course I never had reason to look anywhere else, and Grams' search sucks. So instead of combing one-by-one through every market ever listed on dnstats, I thought I'd ask the hive mind first.
I don't see why you wouldn't be able to find it through Grams.
"VanillaSky" or "GHB" and pick through the results.