There's some cheaper ones around but with varying quality. I use Cycliq front and back and they're not perfect (the app is rubbish and it's surprisingly difficult to get both cams showing the same time), but they're currently the best for ease of use (e.g. overwriting old recordings automatically on the microSD card).
Yeah they're pretty good on balance. I've not seen anything else that gets the core features so right.
The only thing that really drives me nuts about them is that they have a tendency to come out of Airplane mode by themselves. Bluetooth gradually drains them flat if I don't keep them constantly plugged in.
Since I've never really got the Ant+ networking to work reliably either I could probably do without any wireless features.
Oh and I got mine on sale for about half what they normally go for
...and put the savings towards another bike obvs. (n+1) (s-1), etc :D
For a while a long time ago I used the monoprice action cam (discontinued). It looked like a bike light, didn’t have stabilization but had an easy to use big switch on the top. Worked well enough but along with my bike light it was another thing to charge and I didn’t have time to go through all my footage.
Recently I’ve attached my go pro and it being much newer is better and digital stabilization but the battery life isn’t great.
So I usually ride without. But I have a cell phone in my pocket..