The prize of 7 million dollar is waaaay exaggerated and is best to be forgotten. I agree with Luke: 1 million is already overpriced and is the maximum.
The parure can be purchased however for Fifty Golden Years. Despite the problems in the marriage (Juliana & Bernhard had, Albert & Paola had, etc.) there is a milestone. Doña Sofía is not only the King's wife, she is also Spain's Queen and a Princess of Greece and Denmark. She deserves it to get such a nice royal cadeau.