I think that in metal, pretty much everything sucks in terms of money! Since the crowd/demographic is smaller, bands don't make as much, IMO anyway. Guarantees for popular metal bands are still relatively low compared to the big acts of yesteryear. So you have a trickle down effect to local/regional or unsigned metal acts...Which means no money!
We've been direct support for what I'd call "big" names in metal (Anthrax, Arch Enemy, God Forbid, LoG, Unearth and a ton more), and it's always varied, but never really that much (mmm, say 150 bucks to play the show). But, we get no stipulations on merch sales and we keep 100% of our merch profits at the venues (which isn't always the case at some).
In Indianapolis, most of the bands in the scene have a staunch "no pay to play" stance and any promoter viewed as a pay to play promoter gets a bad rep pretty quickly. We still have some bands who do pay to play fests (Milwaukee Metal Fest comes to mind), but pay to play has pretty much been ran out of town here, or never really taken off. Most bands just play for free. We have a pretty good all ages venue in which some good nationals come through. For locals, they have a deal set up based on draw. There are no alcohol sales, so door money is the only source of income (aside from sodas, etc.). The more bodies through the door, the more percentage the band makes. At bar venues where we've done well, we get a pretty decent amount. At one bar that's kinda become our "hometown", as the headliner we get ALL the money that goes to the bands and decide among ourselves how much the opening bands get. We usually split it 40/30/30.
Any time we host shows or book our own headlining show, we in effect become the promoters, even at established venues. As such, we always try to treat the out of town bands to a cut first...They drove the farthest, have the most to risk, so we want to compensate them first. So, when we show trade and play their city, hopefully they will reciprocate. At times, we've even taken from our own merch profits and given moeny to bands if the draw didn't generate enough revenue.