Cost was about 25USD. I was lucky to find a local place where I dropped off and picked up, so no shipping etc. Removing and re-fitting the case, whilst a little fiddly is very easy, just remove all the screws and slide off.
I was surprised the screen printing remained intact, I was prepared to lose it.
Reason I wanted black is that this is in the living room, for both headphone and speakers, on a rack with all other items being black.
I also added some different feet, black aluminium from ebay.
None of these changes effected the sound