IMHO this is the only correct answer. Some of the smallest asteroids clock in at Quintillions of dollars of value for their minerals. Even if only 1% of their value makes it dirtside that's a big ol' chunk of dosh.

I hope I can live long enough to see the effects of asteroid mining on the world and the economy.

Palladium today is $1704.73 per ounce, but the price of palladium comes from the fact that it's extremely rare on Earth. But what if someone comes back from an asteroid with an amount of palladium that suddenly triples the worldwide supply? What will the effects be on the price point? I'm sure the costs of getting it back planetside will be factored in and slow down any inflation, but I am still curious.

And what kind of things could we create, given a vastly increased supply of rare elements?

If you have a stranglehold on an exceptionally rare resource, I'm not sure it would be a wise business move to suddenly triple the world's supply.

Yeah, probably would be best to take the De Beers approach and bury 99% of it in storage.