When merch is sold at live events, tax is already included in the price of the items. It is not added on top of the price, like it is with traditional retail.
For example, when you sell an item for $25 you do not add tax on top of that to be collected from the customer, as this would result in uneven dollars which you'd need to make change for. Instead, the tax is already part of the item's price. This is Inclusive Tax.
Inclusive tax is calculated using the following formula:
Tax = Gross Sales - (Gross Sales / (1 + Tax Rate))
Let's say we have an item with a sale price of $100 and the tax rate is 9.25%. In this case, the calculation would look like this:
Tax = 100 - (100 / 1.0925)
Tax = 100 - 91.5331808
Tax = $8.47