Look into these license's VERY carefully before you just jump on board. They are a hell of a lot more expensive than you would think. The royalties add up, then your vendor royalties, paying the artists, devoting months if not years of your own time into the project and when it's all said and done maybe you get 10 - 20% of the sales... What if it doesn't sell all that great? Epic fail and it hurts... BAD!
Don't come down too hard on royalty-based engines. As an indie developer, this is still a very lucrative way to go: quicker development of your game on time-tested platform-spanning engines means an earlier release and less time spent in negative-income development. And many indies won't necessarily have "artists" or other team members to pay (especially solo developers), depending on their skillset. The only thing you can guarantee is that no two developers will take the exact same path to that first paycheck, but I wouldn't throw out the Unity/UDK idea altogether.
Unity does not charge royalty / per title fees only a flat license fee and only for revenue in excess of $100,000 or for Pro version obviously
