Q-Parts Dome Potiknob Abalone CR

As above, these knobs are a bit "Bling" but they're quite fun, I've put four on a spalted maple Les Paul kit build. The abalone inlay is bright and colourful, each one being unique - so it must be real ? I do however think they are a little pricey for what they are, especially if you need 4. They come packed individually with an allen key each, so I now have 4 keys. How much does this add to the cost ?
These knobs are well made and finished, but would be so much nicer if there was a way of fixing them without the visible grub screw hole. Of the 4, I have one which is reluctant to sit straight on the post so doesn't rotate very "square" which is a little irritating given the money spent and the care taken over the whole build, hence my score.