An alternative businessplan you can consider, could be like Marco Wobben has with the DBXpress-driver.
You can give it for free, but ask money for the source-code.
When it works good, I guess you can sell some of your source-codes.
You could also have restrictions on the binary only version, for example, not to use for commercial projects.
That is my intention, already: a free use for non-commercial projects and a paid one (maybe including source or not - didn't decided yet) for commercial uses.
If I decide to not release the code for the normal commercial license, I would always sell the code to interested parties.
Maybe I would be the source-code, just for not being dependant to someone else for a critical driver in my software projects.
I am glad I bought the source code from Marco Wobben, because he does not want to do some small changes I need.
Yes, that is something I understand very well... I tend to look away from closed source software/libraries for the some reason.
Thanks for your comments, I will take them into consideration.
As you may have noticed, I don't have any fixed idea on how to do it. I think only when the project is done I will have a final decision.
Regards, ~Nuno Lucas