If not, that must mean the product is fake since the materials are not real.

Genuine question. If you can source inputs in bitcoin makes all the difference financially. Every business is different but if you have to pay all the inputs, cost of goods sold, labor, insurance, taxes, rent etc in fiat then only payment in Bitcoin can be innefficient. A balance of cash flow currency is actually very useful. Buying sats with profits can make more sense at times than using a product as a means to obtain sats thru fiat capital expendature. This is the weird problem small business faces with bitcoin tax and hurdle rate. Bitcoin as an investment doesn't return enough to pay monthly bills. Additional income is needed to pay fiat bills. But nothing you do really beats annual rate of return.

Whenever I can, yes. In an optimal world, I would be able to buy it all with sats. This is why I push for using bitcoin as an MoE, and not just a SoV.