Good noise-canceling headphones last four or five years if you treat them right. You are buying quiet for deep work, travel, or long commutes, so buy once and get a pair that actually holds up instead of replacing a cheap set every six months.
Audio brands drop new flagship models every fall. That makes late summer and back-to-school sales the best time to grab last year's top-tier pair at a deep discount right before the new ones hit shelves.
A 0% intro APR gives you breathing room, but it is not free money. The 15-month window is a hard deadline, and if you carry a balance past it, standard interest rates kick in on whatever is left.