The PoA and PoAU sets had the diamond-foil/holofoil sets too.
Why didn't they produce the holofoil for SS and GOF?

That is my favorite!!

Well, I suppose it would have caused an uproar by a lot of collectors who would have said, "OHHHH NOOOO! Artbox is doing it again! How much money do they think we have...Are we made of money... another rip off by Artbox. Yadda-yadda-yadda----ditto--ditto- ditto." Or assorted other words, I venture to say, not suitable for a family forum.

We all know there are some, whom shall go nameless, that want 30 or so of each set. You know , for their various nieces and nephews. Well, OK, maybe I'm exaggerating. No one would do that...would they? Me, I would have bought one (1!), too.
You know what would have been a really neat thing to have done was to make the foil corrrespond to the color used on the book covers for each set instead of the usual silver and gold. We all see how nice the red, blue and green foils look on the Promo cards.