I see a lot of excuses and sidestepping in your posts. Blaming e-commerce and others for your business practices. It is a shame that your customers get treated in such a way. Ordering custom and made to order does not demand 100% of operating cost and 100% of profit be paid upfront. Nothing special about e-commerce to dictate that model either.
Coincidentally, I know something about custom furniture not made in NC. Our single largest expenses are electricity, fuel and taxes. The secondary is depreciation and materials. Time goes against profit. This piece was crafted from black walnut and holly.