Actually I believe the gunslingers were getting paid $20 a piece in The Magnificent 7. It was the fact that they were willing to work for so little. It was in The Seven Samurai where they were simply offered room and board.
Mercs vs Gangsters? I suppose that could work. Maybe the cartel forces the young men in the village to work in their cocain/poppy fields as slave labour, harvesting their crops. They can maybe offer the mercs whatever riches the Boss has in his mansion to entice them?
You can certainly get most of the template characters from the story in this scenario. The wise leader, the veteran who lost his nerve, the greedy one who's sure there's more to it, the good hearted one who's there because it's right, the annoying one that no one likes but is very skilled, the old pro who's there for the challenge.
But what about the youngster who wants to be like the others? In Seven Samurai it was the young Samurai who asked to be apprenticed by the wize one that first agreed. In Magnificent 7 it was the young gunslinger who worshipped Yule Brenner's character. In Battle Beyond The Stars it was the guy who went out seeking warriors to save his planet from invasion. In Mystery Men it was Invisible Boy. How would you team up a young soldier with a bunch of old timers and make it work within the context of the story? I'm not saying it wouldn't work, I'm just wondering how that last part would work.
