Your finding looks way too cheap for a complete key. But it's "
master key" is uncut!
Regarding operating frequency, if you ever wish to use it, be aware it can be wrong for your car:
http://www.realoem.com/bmw/enUS/show...diagId=41_2892. Your red trim means "Sport Line".
Here is a similar DIY story:
https://f30.bimmerpost.com/forums/sh....php?t=1350048. I see empty key shells on ebay.co.uk, like the one mentioned, quite cheaper than your complete key finding. I'll skip direct links, feel free to search for "Replacement 3 Button Smart Remote FOB Key Case for BMW F20" (no quotes). And by the way, the complete key can be glued as it seems/stated!
Here is a simple disassembling video:
.