I've played (against) these with friends and it's certainly fun if you want something different during an evening of MTG. We've even mixed in the Hydra variant and played against all three with like 4 players. Granted, not much variation like user @ced1106 said but fun nonetheless. Also a nice way to test a new deck.
Don't know of these are competative prices as I don't live in the US.
Don't know of these are competative prices as I don't live in the US.