There is nothing wrong with dynamic pricing in itself. Anyone who has bought an airline ticket or a space in an airline carpark will have experience of dynamic pricing. The price changes periodically from when it is first offered on sale. There is dynamic pricing with football tickets in banding of games - or if you take advantage of 'Happy Hour' in your local.
There is a problem with changing in pricing whilst a customer is trying to buy a ticket and finding the price has changed whilst they have been logged onto website. At the moment a customer enters a company website trying to buy a ticket for an event, that should be the price at checkout. In other words, prices should be clear at outset and should not be changed once a person is trying to buy a ticket.
(Just to relate to Oasis tickets - pricing could change for new customers whilst on sale, but not whilst someone is in a queue.