Paul, I agree with you about the sailing date. Our upcoming cruise to Alaska, at the time we were looking, (Sapphire Princess) had prices the week of 6-27 beginning at $606 p.p. Every other summer week was priced about $200 more p.p. on the exact ship.I'm not sure why the week from 6-27 to 7-4 was not booking as well as the other prime summer weeks, but it worked out well for us.
A couple weeks after we booked, the price of this cruise went up to about what the other weeks were priced.