Yeah, it's a good question and one I don't have a strong opinion on. But I will say, I think those guys and gals still provide value to the UFC even if it's not directly related to attracting eyeballs. I've made this comparison before, but nobody is tuning into the NHL to see the average 4th line left winger. They are watching for the McDavid's, Crosby's, Ovechkin's, etc. But that 4th line winger makes $750,000 per year because they are still providing some support to the NHL and helping to some degree making it what it is. I don't think the number for your average prelim fighter is $750,000 per year by any means, but I don't really have a number in mind either.
Yeah which is why a union is so unlikely. Everybody is just looking out for #1, but it's hard to blame them. They've literally fought to get to where they are. If they have an opportunity to make some money, they are going to take it. Look at the whole Tony-Poirier thing where they both told the UFC to go pound sand.....until Poirier got offered Conor. Or Jones wants too much money, so they do Lewis-Gane for an interim belt. There is almost always another option the UFC can use to get things moving again. At some point, the fighter will need to make some money and come off their asking price. It's how the UFC has got to this point without having a union.
I'd also like to see the win bonus go away. I really find it hard to believe fighters need more of an incentive than the guy across from them is trying to hurt them. Not to mention a win advances their career. It's just kind of sickening when someone puts it all out there, maybe loses a razor thin decision, and gets their pay cut in half because of it. Or worse, gets screwed by the judges. Even if they end up getting knocked out, they get salt rubbed in their wound. Just pay them both higher show money and get rid of the win bonus.