You can publish as often as you want and without royalties with the standard license.

More than 99 percent of us will never publish through a big publisher. So we do not need the professional license.
You can be happy to sell your product for 10 bucks at a few casual websites.

But if you have the next crysis-killer, then you have spent so much money that the professional license will be peanuts for you and your publisher.

So this is not really an issue. First make your killer game with standard license and then see what happens