Ship and towns (Ketchikan, Juneau and Skagway) are a giant vacuum cleaner for your last cent. Consider the cruise either as transport to additional pay-for tours, or a temporary hold on mundane concerns. There is little to see from the ship itself. Customer service from Princess is abysmal.
The good: 7 days of the cruise provide room service, food and diversions on the initial fare (but see below). Ship staff is plentiful, courteous, though often uninformed.
The bad: the room (cabin, “stateroom”) is minimally larger than the bed, the shower stall is minimally wider than one’s shoulders, the food is mediocre, the diversions mostly unremarkable or worse, but delivered at excruciatingly loud volume and pervasive presence. Public restrooms are in short supply.