Sorry for another comment - but can you tweak the quartz trade proportions in the next update? 100 gold for only 100 quartz seems pretty unreasonable... haha!
No worries. As for the Gold-to-Quartz trade, it's actually meant more as a way to recycle any unused Gold Ore rather than being a profitable exchange. The main way to get Quartz is still through digging, with a bit of luck from the slot machine as well. That's why the exchange rates at Bits & Bobs are intentionally a bit rough.