Can you give an example for the spike you are seeing ? Comparing older copies of the Materials page as saved at archive.org I do not see a recent change. (That is unless they had new prices up prematurely last night and reverted to the old page as there had been no announcement yet).
Could it be that you are comparing Euro prices, which are frequently adjusted according to the exchange rate ? (The Euro currently trading for ten percent less than it did six months ago is likely to have a visible effect on the price of expensive items here, unless you are comparing to purchases from a bit over a year ago when the exchange rate was roughly the same)
Another possibility - if you are looking to buy a specific product from the shops - might be simply that the designer raised their personal markup for that item.
EDIT: or maybe I misunderstood you - so what "spike" do you mean ? As far as I know there has been no significant increase in commodity trading prices either, so are you referring to a perceived spike in demand for 3d-printed premium jewelry (which could be anything from approaching holiday season to internal orders for tradeshows) or just the relatively recent addition of such metals to shapeways' range of materials (which does not necessarily mean that there is demand, just that their casting partner would be able to process such orders if needed) ?
Last edited: Sep 26, 2014