The Holders are the Parts that hold the Material in the Machine... For Crystals for exsample they must be made so that the Crystal can be Sputed from both sides.
The Ceramic Bezel must hold also in the Machine... There must be an distance from the Sputter and the Particels etc.
For more info check google or Wiki... There are masses of information... Check for DLC, Coating, Sputtering you will find a lot of infos...
That what your guy did is not more as an DLC Coating the same that we know from Watch Cases in Black, RoseGold or or or... The same Sputtering Process would be done on the Ceramic Bezel...
So i don´t need to ask your Guy from HH i have ask self an half Year ago Big Companys who would do that job... And the Results are all the same...
An good Sputtering will be around 2000-2500,-Eu the holder will be around 250-500,-Eu for each piece... As i already said... The Maximum of Crystals that can put into an Machine will be 30 Pieces...
So you can Calculate 2500-3000,-Eu / 30 that would be the cheapest offer you´ll get... Maybe if you know your Watchsmith, he can make you an better Prices for the Coating.
That could drop the Price a little bit, but it wouldn´t be much...
I am pretty sure... But check what you can do...
Let us say the Price stay at an Calculation of 150,-Eu per Piece, i can tell you what will happend.
The People tell you wohooooo i will take one, i take two another one want Five etc etc...
Then you start an Slot List... 30 Slots for the first Batch... The People write there Name in the list...
You think cool so we have 30 Slots let us start, then you write 30 People an Mail and 15 of that never responce anymore... They play dead...
So you ask for other People you fill the Slots again and the play start from beginning.
The best part comes then when the People should send you the $$$ and there Ceramic Inserts then you will get only the half of Slots...
The other half that have send makes you Preasure when you will have the Finished Product?!??
And then there are two options.
1. You pay the other half self
2. You drop the Project send all Stuff back to the Customers and they are really pissed.
You don´t believe???
Ask Edgematic or Mikey2008 or or or... There are sooooo many good guys here that have try to give the People nice updates... But the most of the People don´t respect there work or what ever?!??
They don´t use there Brain... They set first the Name on the list and they make then the decision...
When you choose variante 1.
You pay the other half of the Batch you would be maybe sell the Complete Batch after an half Year or so...
When then all Inserts are away then the People cry again! buhhhhhhhh no inserts what the F.... i want one...
Then i ask my self everytime why you cry now??? Why you don´t send the $$$ at the first Batch as Modder have ask...
So i which you all luck of this World!!! If you can bring us all an nice updated Insert for an good Price why not... I am in !!!
But not with the SubC and GMT insert

but with the SD and DSSD
But Remembe the Platinum Effect must have for that Price the same Color as the GEN... Because the newer Inserts that are out are already DLC´d !!! But in Silver... And sooooooo Bad they are not...
Much much better as the first White Painted Inserts...