2wd's don't seem to be as common as 4wd's. But I do see them around somewhat regularly. I probably run across at least one 2wd trackick, every 2 or 3 months.
Are you talking tracker tcase gears, as far as no one having much? If so, I agree, I think the only tracker tcase gearsets you can get are the 4.24:1's, which are higher in cost than the 4:1 samurai sets. So if you can add the samurai tcase in for little to no $$$, then you could turn around and buy a samurai tcase gearset and still have less money invested than just buying the tracker tcase gears.