Paypal does not charge sales tax. In some states it is required to add sales tax to the item purchased. Here is an explanation of how it works!
https://www.taxjar.com/guides/sales-tax-guide-for-paypal/#the-basics-of-sales-tax-in-the-us
https://www.taxjar.com/guides/sales-tax-guide-for-paypal/#the-basics-of-sales-tax-in-the-us