Don't buy them all and ebay them, that's silly and greedy, and you probably wouldn't make much anyway. Just buy what you need and use them. They aren't that much better/worse than dura ace cogs, which cost about the same(maybe a little more, bensbike has them for eighteen bucks).
And Suntour was not the only company to make 12t cogs. I have a 12t dura ace cog to prove it, 10 pitch at that.