I got this one for $70:
http://www.ebay.com/itm/310585954574?ss ... 1497.l2649
And this one for $56 (price has since dropped to $50):
http://www.ebay.com/itm/260900800763?ss ... 1497.l2649
They both came by China Post by the same method (airmail) and in identical boxes and wrapping from the same town. The $70 one arrived 6 days faster, which I assume that means the shipper sent it sooner.
The plastic housings are identical.
The angle of the lenses seem the same outside. When I shot a test image, the $70 one may be wider.
The menus are a little different.
The $70 one has more saturated color on the display.
Both are H.264 and make singular file sizes.
The $70 one has higher sharpness in the recording, but also more noise. I am not sure that it has higher resolving power.
On this test target, the $50 one appears to be higher resolving power, but I think that is simply because the lens is a little less wide angle. So the sensors are probably equal in resolving power and the lenses are probably equal sharpness. The $70 camera seems to use post-processing to bump up the apparent sharpness (but not actual detail).
Wish - it would be nice to be able to use less compression - I don't need 20 hours of recording for a 32 GB card. I would rather have 10 hours and fewer compression artifacts.
There is no obvious difference which is better.
This is 1440 mode - not better!