Money Laundering
Treasure
Cost: $5
$1
Return a Treasure card you have in play to your hand.
Interesting, and not necessarily a really bad idea. Crown has shown that playing a Treasure twice isn't overpowered, and Money Laundering is quite close to being a Scepter for treasures in most cases. It's not often that you'd draw Money Laundering after playing a Treasure, and not often you'd want to to do anything with the Treasure other than play it again. The corner-case exceptions might be enough to make it fun.
The $1 feels unnecessary, though?
I also think that it could be interesting. It would create a nice combo with Capital (better than Crown, because you could play the same Capital more than twice). I didn't think thoroughly about it, though.
The $1 probably makes it an RBCI
With the current wording, you can trivially create endless money. Play "Money Laundering", get it back to your hand, play it again and repeat.
EDIT: (I know it's RBCI but anyway) Also removing $1 would not be enough. I guess 1 Counterfeit + 1 Money Laundering, which would be great in terms of theme, could create endless money and buys. It could still be a nice card after some changes.