Motorized shades are about making your home run smoothly, so you want motor hardware that lasts ten years rather than cheap sets you replace in two. Spring home tech promotions are the best time to buy, especially when manufacturers flush out last year's inventory to make room for minor updates.
Last year's models usually offer the exact same motor reliability for a fraction of the price. If you map out a steady paydown strategy, you can get a full $1600 setup working today without paying extra in interest charges.
Keep in mind that a zero-percent period is a strict deadline, not free money. If you still have a balance when the 18 months ends, the regular interest rate kicks in on whatever is left, so stick to the monthly schedule.