My GUESS, as a mini gamer, is that we're looking at metal minis, with an outside chance at prepainted rubber (Well, 'plastic') ala HeroClix.
Metal minis are the cheapest to make, where you get a mold that can spin up metal into a frame, creating standard miniatures. IIRC, a mold that can make twelve minis a spin runs arond $2000, withe the number of minis in it based off of size.
Let's say that you start with six factions, each of which fllls up a mold, and then a 'mercenary' faction for the seventh. That'd be about a $14,000 investment, plus the rulebooks, art, advertising, and so on. Not a *huge* number, but enough to make people like me go, "Well, that's what I make in a year. Yipes."
Plastic molds need a much different machine. Vacuum molding of plastic is trickier... the molds last far, far longer than metal ones (After about a thousand spins, metal molds will start losing some detail. By ten thousand, you want to replace it. I *think* those are the right numbers. Plastic can generate around a million presses.) but are also more expensive. Again, IIRC, each plastic mold is $20,000 (Tho I have heard as low as $10,000 for the Clix style) ... that $14,000 start-up is closer to $140,000 with plastic.
So, plastic is better for the long term, but if you don't know if it'll be a success or not, you go metal.