And therein lies the problem.. I personally would not be disappointed in anyone, especially Rodel, if they decided to not send theirs in to be replicated. In fact, the outcome is likely going to be more exaggerated than you think, which is why Kaminari is interested in the first place.. everyone appears to genuinely want one of these, and there are enough owners with money (seeing as how this isn't pre89 vs 89+, etc).
So, two things can happen: the originals lose their value, especially since the new ones will in fact be new originals (Kaminari itself would be reproducing them), and a bunch of people will have these on their cars thus decreasing another big detail of a part like this, rarity. Now that I've considered this to the full extent, I can see why Rodel possibly wanted to have Shine do this instead of Kaminari; originals would keep their high price and rarity, but others could buy the copies for aesthetics and at a cheaper price. I should have realized sooner, and no, I do not think it is selfish to look at it this way.
Of course, most of this could be avoided if Kaminari set the price point of these up high enough to deter anyone who hasn't actively been searching for one regardless of price (unlikely).