They look like actual stones, for one
Bandai Namco has been trucking away at various toy lines for competitors for years, but this time they really caught my eye.
I doubt I’ll actually pull the trigger given that I don’t want to start a bigger Pokemon collection, but they’re peddling a trio of Evolutionary Stones (Fire, Water, Thunder) in early 2018. They’re going on sale in February in fact, and right now they’re only going to be sold as an import, and will run you 5,400 yen, which is roughly $50.
They’re big enough where you can hold them in your hand, and they have an actual picture of what they look like out of the box/free from promotional materials. Compare these to the Infinity Stones, a collector’s item gone wrong in the recent Marvel vs. Capcom: Infinite set.
Evolutionary Stones [Bandai]