Be aware that if your historic site employs a below cost pricing strategy and a price is set too low, there can be a decrease in demand. This “price paradox” occurs when a customer, due to the low price, believes that the experience they are about to have is actually not worth paying for.
Similarly, if the price is set too high in an attempt to maximize revenue without a strong value proposition for the customer, then of course some customers may consider going elsewhere with their time, interest and money. A value-based strategy, and certainly a luxury strategy, rely on your organization to create and convey a unique, valuable experience for the customer.
A note about “by donation” admission prices
There are exceptions — where an average donation per visitor will exceed the costs of providing the experience — but unless very specific marketing and engagement measures are taken, a “by donation” pricing strategy will invariably lead to lower revenues, lower return visits, and will typically also lower the perception of value for a visitor to your site.