The only relevant card type that it cant exile are planeswalkers, and generally, there are other ways to deal with them
Tamiyo is a sweet build around Commander, offering a nice little hoop to jump through and a reasonable value engine on the other side
The best of the lot here is actually a sorcery: Sea Gate Restoration, a big and powerful draw spell which masquerades as a land if we need it to
Real currency can be spent to purchase gems in the game, which is why they are more valuable and harder to obtain
Im not sure how relevant The Ring tempts you will be to me in the long run
It gives you consistent value with a scry 1 every time a creature ETB's under your control, and the second time that happens in a turn, you get to draw a card