Hell. Another Point.

Do tell ticket-buyers up front about those pesky per-order or per-ticket "convenience charges" so that they are not surprised by additional charges added only after they click the Check Out button. Your audience members' blood pressure may rise at the sight anyway, so warn them in advance!

Do consider dropping them entirely by rolling legitimate costs into actual ticket prices! It is galling to be an out-of-town visitor who cannot just walk up to the box office to avoid these charges. If it's a per-ticket charge and you're planning to visit NYC for two weeks, attending six opera performances, those $10-per-ticket and $2.25 fees add up mighty fast. Yes, that means you, Metropolitan Opera.