Do I need to pay again for Themes/Text style that I have purchased if I want to use it again?

No. Themes/Text style that you have purchased can be repeatedly used by the same account you purchased them with. If you have cleared any downloaded Themes/Text style, you can search for them in Themes and download them again. If the BUY () button displays, touch it to go to the download page. The payment page will not display.