Xondat is still waiting on the prototypes to be made and shipped. Let that happen, and let him make any changes necessary at that stage.
I'm sure by then, you will be able to get a more exact figure for an estimate. Obviously for such a small run of products, the price is subject to change based on changes to design requirements, this is a given when you join such a niche group buy for what is essentially a very premium product.
I don't think the prices of anything will go up that much compared to the original estimate though, but if anyone really doesn't want to pay that little bit over the initial estimate, I think there are plenty of people in the line that would take the place.
I'm looking forward to seeing what the different colours look like, just to make sure that I still definitely want the grey over the black!