A few comments about the Volume of sales:
1.
Know your limitations as far as volume goes. I once had a major retailer ask me if I could do a line for them, but they were talking 50,000 handbags . Even though we do a sizable volume- there's just no way to scale up like that. If we even had tried we'd have had to abandon all our old wholesale accounts....and if they canceled in a year or two, where would be be?
2.
Another thing to realize with volume is that "economy of scale" doesn't always apply with leather work- For example if a customer wants 500 pouches all in the same color, I can find a batch of scrap or a few hides that I've gotten a good deal on and sell for one price. But, if a customer asked me to do 10,000 all the same color/same leather, we'd have to go about buying hides and the price per piece would be substantially more. It's entirely possible that 500 pouches would be substantially less per pouch than 10,000....
Just my 2 cents after doing this for a while...