Shannon,

Standards and benchmarks are helpful in some cases, but the costs of developing and mounting exhibitions varies so widely, as do the scale and attendance expectations of museums, that I don't believe there is a true industry standard for the ratio you are looking for. For example, a $500,000 exhibition might be intended to serve 50,000 visitors at one museum ($10 cost per visitor), and 500,000 visitors at another ($1 per visitor).

Every museum would need to decide what the cost per visitor is worth to them.

If it is a pure business proposition (as in wanting to create an attraction that will pay for itself through admissions income, or a traveling exhibition that you want to generate more income through rentals than cost of producing and maintain, then you might need to use more complex budgeting formulas). You could start with price point and work backwards, but I would start with vision and objective for audience and institution and then figure out what the costs would be to meet those mission-based goals.

For planning purposes, you might extrapolate some helpful guidance from ASTC's Statistics Analysis Package, a helpful compilation of financial, attendance and other data from museums in 2012.

Good luck!

Paul