double-blind study - an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment; a double-blind procedure is used to guard against both experimenter bias and placebo effects.
No they get more expensive, airlines will always advise you to book in advance to take advantage of their best fares. Sometimes they do a special deal but not within a week of flying. I would try another airline or make different plans.
If you do book early and see a promotion come along closer to sailing that offers a lower price, contact your travel agent to see if you are eligible for the lower price. In many instances, the cruise lines will honor the new, lower price and you still get the ship, sailing date and cabin you wanted.