Turkey hunting is not high volume shooting. And compared to other hunting expenses, $10 a shell is cheap for the just about best there is to use! If you don't want to use it, don't. If it wasn't for TSS shot, I'd never consider a 20ga let alone a 410. And I know people use those succesfully with lead shot. This is all what you want to make of it. I don't use TSS to shoot long range, though you sure can. Hard to argue with the pattern densities though, or the penetration from a #9 piece of shot.
I'm just about done setting up another 20ga dedicated turkey gun, another 870. Lightweight, easy to carry and gets the job done! Really looking forward to these spring seasons!