DJI via eBay offers its refurbished DJI Phantom 3 Professional Quadcopter with 4K Camera for $479. Apply coupon code "PBACK2SCHOOL20" and check out via PayPal to drop that to $429. With free shipping, that's $70 below our January mention of a new unit and the lowest price we've seen for this model. (It's $170 under the best deal we could find for a new unit today.) This quadcopter features a flight time of 25 minutes per charge, 4K video recording, 12-megapixel camera, and 3-axis gimbal. Deal ends July 16.

Note: This coupon can be used twice per account.