DvG is a bit of an issue imo. There isn't anything else like it for getting loot. the cranius buff is nice but that's 4 drops once a week which I feel is waaaaay too long. Besides that you could either do rampages/cleanups or the titan secret for loot drops.
Having about 78 hours in this game all the currencies I have stacked up is insane and there should be something to spend them on other than just mods. I've got 400+ yueco 700+ everything else and 3000+ gats and it just sits there. I like your idea for the "greedy merchant"