Budget GoPro Seat Mount

I wanted to get a mount for attaching my GoPro underneath the seat of my bike, but I didn't want to spend ~$60 on this K-Edge mount (as nice as it is)

Looking at the top of my seat post (Crankbrothers Cobalt 2) I found it had this bit in between the rails that looked like I would be able to easily mount something to it.  Unfortunately I dont think all seat posts will be the same as this.

So I went to a Glass and Aluminium shop and picked up this off-cut:

Drilled a few holes in it, then bolted on a standard GoPro tripod adapter:

Then bolted it to the top part of the seat post:

And here it is on the seat:

I'll take some more pics once it's all back on the bike.

Total cost was $5 for the aluminium and $2 for the bolts.  GoPro tripod adapters sell for around $12 - $15 but I'd already bought that for something else.  Much cheaper than the K-Edge mount but it should be just as sturdy.