As the vice president of a 501c3 non-profit here in Ohio, we operate a small museum dedicated to the area's history. I can tell you that if we relied upon admission fees and free will donations, we would have folded long ago. Museums do not make money and anyone who thinks they can by opening one has a surprise coming.
Museums are meant to tell a story and be a part of the community. Their support is to come from that community, whether the community is a collection of residents within a geographical area, or a group of people within an organization.
Reading Jay Leno's issue with the woman that fell, insuring for liability can be one of the single largest recurring expenses for most museums. Our premium easily runs four figures a year and some of the larger museums can pay much more to deal with the inevitable lawsuits.
But, for those who want to open a museum, if done properly they are a rewarding experience. When the scout and school groups come thru our buildings and the docents tell the tale of life in Geauga county in the 19th century, the kids are riveted to every word. That makes it all worthwhile.