I've got 1L (more than enough for 2 front seats, rear and door cards) of black PelleCare leather restorer. This is not a cleaning/condition kit, it's complete restoration. You strip the old leather colour coat first with the included solvent (or meths works better IMO), clean up the mess, let it dry fully and sand with fine grade paper. You can fill any really bad cracks with leather glue then apply (by hand) the PelleCare product with a sponge or cloth.
It has a latex filler in the paint that fills most cracks and marks in the leather.
Not suitable for changing from the original colour but will bring your seats back to great condition.
There's a video of how to apply on my project thread here. I ordered an extra pack as I'd used the first one on my 528i but managed to do the 540i as well without opening the second batch so it's surplus to requirements.
The kit retails for $150, yours for $95+shipping.
BOOM.