"Even a well established non-profit such as Pinewoods, Hurdy Gurdy, Clearwater, or Folk Project make money off their events."

With all due respect, you are making an assumption with that statement and I can tell you that in at least two of the organizations you mention it is not true.   

I will say that the Hurdy Gurdy does earn money during our regular concert season (which goes to operating costs and donations to other community events. No volunteer makes a dime.) When we produce a "benefit" concert there are different policies in our case. There is a difference between paying expenses and making "money off" an event.

Please don't get me wrong – I think what the Borderline is doing is a wonderful thing. I applaud you and your volunteers for taking on this worthy cause.

However, you cannot make assumptions and then blame other organizations like Shop Rite when they are trying to do the right thing.

You are no longer a private party once you advertise and invite the public - as you do here on Mudcat and your website. House concerts deal with the same issue. The wording of your notices does not come across as a private invitation.

Your initial posting in the other thread reads :

"There will be a Mystic Festival preview concert at The Borderline Folk Music Club of Rockland County, NY on Sunday, April 19th.

The venue will be the New City Volunteer Ambulance Corps. building located at 200 - Congers Road, New City, NY 10956 (across the street from Clarkstown North High School.

We will start the festivities at 12 Noon and run until 5 PM.
Admission will be $20 per person with all proceeds going to Friends Of The Festival. We will begin with a pot luck lunch and 12 Noon."

No mention of private party or even "suggested donation". You call it a concert and state an admission price. You invite the public.   

You can't have your cake and eat it too, and expect not to pay the baker!