A store advertises 15% off an item that regularly sells for $300. How is 8% sales tax like an 8% increase? Explain.

From what I understand, a sales tax is making a customer pay more. therefore if your charging 8% more, the price is being increased by 8%. For example: 8% of $300 is $24. So the actual price would be $324, with a 8% sales tax. therefore it is a 8% increase