Bought one ofF these last week - fantastic service and quick delivery.
£15
Just type in your GS key number (K1234 etc) . You then send a photo of the key for confirmation.
I did think when the key arrived there was no way it was going to work because it looked nothing like the key it was supposed to be a copy of, but it worked fine.
Goes to show though there appears to be a lot of detail in the OEM BMW key, what looks like a rough estimate of the cut shape is all that's needed. Either way, for modest outlay I have a convenient copy that can be used only for the topbox keeping the keyless original key tucked away