Buy DBPro. It should be capable of creating any game you could think of (it might not render millions of polygons several times a second though, but you really wouldn't need that either). If you make a game (or any other application) with it, you are free to do whatever you wish with it (sell it, give it away, or place three copies on the loo to brighten up your mornings).
If you find some feature missing from the core package, there are also lots of plugins around to give you whole new features. Or you could write your own C++ plugins and use from DBPro too, if you want.
Also, take note that DB Classic is
not easier to learn than DB Professional, allthough the name might imply it; DBC is just the old, never-to-be-updated-again version, so I suggest you to spend the extra $30 on the professional version, which has a lot of more to it and is regularly updated (the updates are free, by the way).
-> Oh, come on...