it always amazed me when my lens frequented the folk clubs, the fees varied from a jug up to £10. A guest night (and depending on their fame)
can require a higher fee. Surely it is up to the audiance as to whether they wish to attend. A club will only grow and be well attended if the members recieve a good evenings entertainment. Entrance fees maybe a necessity in the 21st century, but it is still our choice as to pay or not.
I am associated with a club in SE london and yes we charge a fee £1 for a sing around and £2 for PA/guest night. That fee also allows a summer and autumn camp plus an xmas nights entertainment. With the exception of special guests when we may increase fee to £3.
Attendance and satisfaction is what makes a club.