I am having a hard time following you on this purchase/trade. The trade at the QQQ will be for a $300, 6oz silver strike that will require 30 QQQQ $10 strikes. It does not matter if the 30 strikes are clad, .999 or a mixture of both. You have not disclosed the metal content of the 35 strikes you have
available, however the QQQQ does not care if they are clad,.999 or redcaps.

Yesterday the spot close was $27.53. If as you say, the dealer charges $1 per oz, that would bring the value to $13.26 per strike. Your asking price is very close to the mathmatical price of winning a strike at the casino. If I play, I could do better or worse than the mathmatical price, but what do I go to Las Vegas for if not for a little gaming?.