Because so many variables affect pricing, there is no direct record of the changes to any one component of prices, other than the person who last changed it. In addition, changes to prices, events, venues, promotions and tax rates should be limited to specific employees, reducing the need to track who changed them.
If you want an indirect audit trail or go back and see the effect of a change of any of those items, you can use the transaction list to look at ticket sales. The key fields to display in the list (and potentially export) are: dates, original price, discount, taxes, fees, final price, tax rate, promotion, price code, event, performance, venue, pricing map and who created the transaction.
Armed with that information, you can look at price changes and see the effect, plus who is mort likely to have made it, assuming that somebody tested the price change (because there should be a ticket sale and refund with an employee name on it).