Know the owner of a failed restaurant. He said you aim for 25% for food but usually it ends up around 33% no matter how hard you try. This was for a single non-chain restaurant.

Someone else about to close a business down for a physical product. He was boutique sized, because of competition from factory made higher volume, he could never get above 2x COGS, and it has been a hard grind that is now losing money instead of the narrow margins he'd had for a while.