You need an ergonomic mesh chair because your lower back is screaming after six hours at the desk. A top-tier chair should last ten to twelve years, meaning you are buying once instead of replacing a cheap $150 fake-leather peeling disaster every two years.
Skip the brand-new releases and look for office liquidators selling like-new stock from companies that downsized. When a major office closes, liquidators dump barely used models for a fraction of retail, and last year's model is usually identical to the current one anyway.
That 0% window is a hard deadline, not free money, and any remaining balance left when the 15 months are up will suddenly start collecting high interest.