When you buy a drone, you want something that stays relevant for a few years so you aren't stuck upgrading every season. Focus on the sensor quality and flight stability rather than just the latest flashy camera features.
Drone brands usually drop new models in early summer. If you can wait until then, you can often grab the current top-tier model at a discount once the next version hits the shelves.
That 18-month window is a hard deadline, not a free pass. If you still have a balance after the 18 months are up, you will start paying interest on the remaining amount.