Funny thing, could not find GL-4 at any local store.
Called the dealer (Mossy Nissan in San Diego) and they have GL-4 75W-90 regular at $6.50 a quart and synthetic at $12.50 a quart. The guy even said that 3 quarts is enough for a full flush! This is the cheapest I have seen.
Funny, never thought I would go to the dealer for anything.