I know that tipping is a hot topic, but here goes...I was going to buy a specialty dining package at 35% off today until I got to checkout and a 20% gratuity was added to the cost. We have done many Celebrity cruises, but I seem to remember that the upcharge was to cover the service cost and additional tipping was optional. The 35% sale is not 35% off with a mandatory 20% gratuity added back in. Do I not understand this correctly? TIA.