If this becomes to be a pattern, however, you have no choice but to ask them to move since you're running a business and not a charity. 

You need to sit down and decide whether you are operating a charity or a business.

The developer is a charity that I support, however, I still want to establish a fair price.

You need to decide if you are operating a business or a charity.

I have a charity golf tourny on the 17th.  

Gotta decide, are you a business or a charity.

Since that time, I have made significant changes in my life including obtaining a bachelors degree, starting a charity organization, getting married, having a child, successfully completing three internships, and starting my own property management company in another state.

However, I've yet to hear of a charity which caters to that market. 

This is your business, not a hobby or a charity.

We weren't a charity but my parents were charitable and knew what was possible for them to do financially.