Many of the cards in Paradox Rift are seeing significant play in tournaments and more competitive, rather than casual, play right now
Still available at a fraction of that price
You can break traditional stat profiles if there is a large enough dose of variance baked into a card
You're going to want to make sure you're getting your mana rocks ASAP when you're playing, so you can be absolutely certain your turns 3-5 are spent casting absolutely massive spells several turns ahead of your opponents
This winter I bought both English and Japanese foils close to $100 USD in Europe and flipped all of them for $200+ and though I was happy with the extent and speed of the returns, I suspect that the buyers may get a similarly attractive exit if they are more patient than I was
That's why, after many years in hibernation, the concept of phasing once again became popular in mainstream Magic