Even going by your prices for the little ones thats effectively paying a 10BTC premium on the 10BTC. Sorry no deal. I don't think anyone's paid 20BTC for a Silver/Gilt in a long time.

You're willing to do the silver set for 6. That's a .5 discount on your individual prices together.

Your individual prices for the brass 1s equal 7. so I'm assuming if youre even slightly sensible you'd take 6.5 for them as a bulk discount.

Now if someone were to take both the silver set and brass 1s, a sensible you would take .5 off again? Thats 6 + 6.5 = 12.5 BTC for the silver set and brass 1s, and thats being generous in your favour..... which leaves a whopping just-under-10 btc premium for the 10.  

I'll just sit and watch now...