"We do ok at singarounds and sessions but the minute we ask people to pay they don't come. Is it just our club or is this happening generally. "

There are people who prefer singers nights / singarounds and people who prefer guest nights. Different audiences that need different marketing strategies.

My experience as a club organiser was:
1. Holding down prices didn't attract people. If you go too far below the going rate for a gig it gives the impression of a lack of quality and discourages outsiders.
2. We needed a guest about once a month otherwise we ended up with the same people cycling through the same fairly limited set of songs far too quickly