Prosper likely isnt going to be the Treasure Token generating machine that it could be when built around, but this card ultimately creates Treasure Tokens and provides card advantage, which is good enough for a lot of cases
There might be some room for tweaking, like maybe commanders above a certain mana value could only pay the tax after the first one or two recasts
Arguably the most reviled card style in Magic, these special Amonkhet cards, with their unreadable typeface, are not awesome
As such, fair to say its probably worth 10k at the moment
Its very important to get card advantage from other sources though since theyll usually trade 1-for-1 with opposing removal
You know, you get to see all your friends from around the world, which is really cool