I would assume that automating a previously manual industrial process is a lot more difficult than just training a neural network. My gut feeling is that 500M is an underestimate.
You probably have more experience to estimate price better, but I guess I'm working off a different premise. I thought the claim to defend is that "if you go far enough into the future, it will be cheap".
A parallel - facial recognition today is a matter of `npm install face-api.js` (or some other library). Advances in hardware and ML architecture design can bring the currently-challenging world of RL to similar levels.
Another way to put my argument is through a question: do you think that even 20 years from now, the cost of a useful RL system will be around $500M (inflation adjusted)?