You are buying a chair you will sit in eight hours a day, so you want something built to last ten years instead of a cheap one you replace in two. High-end brands refresh their lineups slowly, which means you can often grab last year's model at a steep discount when the new version drops.
We are looking at office liquidators for like-new models that cost about $1100 brand new. Getting a top-tier ergonomic chair for a fraction of that takes a little patience and a clear plan for the cash.
That 18-month window is a hard deadline, not free money, and if any of the balance is still there at the end, deferred interest or standard rates will kick in on the remaining amount.