Custom wheel adapters part 2

So i got a rough quote for the 3d printing of the wheel adapters. The cost will be about 17 euros per piece. And i will have to cut the m12 thread on to the stud afterwards myself. I'm eager to hear in the comments what a fair price for an adapter would be. I'm thinking of 25 euros per piece. With this price i hardly make any profit on them, and they're as cheap as possible. This still means that they will offset you 100 euros for one set of 4 adapters. Please comment, so i can see if i should pursue this or not.