I'd like to be able to control what users can do with an application.

For Example.

A customer is allowed to use Option 1, Option 2 and Option 4 but not option 3
Another customer is allowed to use Option 2, Option 3 and Option 4 but not option 1.

By the way the number of options is 10 right now but will probably change in the future.

Here's an example of what I'd like to be able to do. Businesses download our software. They have to contact us and tell us what they'd like to be able to use in our software.

Right now we already control the use of our software. I mean after a customer paid us he will have to enter a code to be able to use it and take the software out of its demo mode.

Right now we work by a mean of levels. It's either level 1, 2 or 3.

For the sake of flexibility we want to let the user pay for the things he'll use and nothing else.

What do you guys recommend?