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.
This is the best time to buy plane tickets for holiday travel. New car models come out, leaving cut-rate leftovers from the last model year. Likewise, bicycles are released in September and last year's models go on clearance. Look for denim and desktop computers on sale after the back-to-school rush.