Does this list matter if I want to buy instead of rent in Mount Pleasant?

A delinquent tax list of the kind referenced does not exist in Mount Pleasant or anywhere in South Carolina, so it should not factor into a buy-versus-rent decision here. That comparison instead comes down to your monthly budget, how long you plan to stay, and current mortgage rates versus local rent levels. Brian Beatty can run real numbers on specific Mount Pleasant listings to help with that comparison.