- 2015/8/14: Added note about e-Bay seller.
- 2015/8/24: Added note that it now is shipped by Amazon, and qualifies for Amazon Prime shipping.
- 2015/12/8: $72 on Amazon currently, and there are some reviews now (and notes from the seller explaining why the iOS app is “untrusted”. Buyer beware!)
The XuanWheel (or is it Xuan Wheel?) just saw a $10 price drop. It is currently $79 at Amazon with shipping from Amazon, so it qualifies for Amazon Prime. This model has four arms, and thus produces an image (or moving video) at lower speeds than the cheaper two arm models.
One of the two e-Bay sellers has them for $69 with free shipping (from China), currently.
See Also: There is also the YQ8008 (now found for $75 on e-Bay with free shipping) three arm unit which has a higher density of LEDs no each arm for higher resolution photos. XuanWheel is probably better at slower speeds, and YQ8008 probably has better images at higher speeds.