[yusina]

> I don't want to do anything for free

I don't follow. That's your employer, no? Do they pay you a salary? So you are not working for free. Sounds like this kind of thing is part of your job. Maybe another dept. but it should be possible to work in another dept, part of the time. Talk to your manager, perhaps a manager in the other dept and if it makes sense for the business then this should work out.

If you want to do this on your weekends and then sell it, that doesn't sound healthy.