Hamish....duly noted that you don't need the money:-)!!!

Seriously:

Surely this is a simple supply and demand question...if the product is good enough (and "sold" properly) people will come out and see it.....the pros should be that much better than the semi's as they have more time to practice and/ or more talent......they should be able to get more people through the door.

If not...should they expect to be full time pros?

There are lots of very good semi-pros around who earn reasonable but not excessive fees in the folk clubs.....surely this should drive true excellence from the pros if they are to differentiate themselves?

Hamish...why should you feel guilty? If you provide an entertaining evening and some people are prepared to pay to see you that's great.....no one is owed a living!