Nicely done. Yes, it's a game within a game.
On paper, I have $30K worth of Alpha flesh golems, but as many people have pointed out, trying to sell would spook the market and tank the price.
I don't need to sell, though. I can just lease them out.
As you mentioned, some future game mechanic may make any particular card ideal for a given purpose. If somebody wants one, they have to come to me.
It's honestly my favourite part of the game.