Having been in the business, both OEM, large detail users, and individual buyers, it is always "shipping".
We would sell pallets of private label to Ford, Chrysler, etc, no problem, as they have computer programs that tie the order to our response to abiltiy to ship and their trucks would be at the dock within 1 hour of the specified time.
Others, they used logistic shipping handlers, and we dealt with that, which kept shipping cost down.
Small orders, 5 cases or less, we were at the mercy of UPS, Fed-X, etc.
It got worse when the products were classified as "hazordus", and that got really costly.
Individual's, well, they got the big stiffy, cost was not in our control but in the shippig vendor.
You don't even want to know about shipping a container out of the country, the paper work alone would make you have to change your sheets.
I do know what all are talking about, for I have to source many items from outside my normal vendor range.
Recently I was going to buy two pin stripping brushes from a vendor. Total cost of the brushes was $22.00 and they wanted to charge me $18.00 for shipping and "handling".
I contacted them and asked them why they could not just put them in USPS bubble pack for $6 and send them to me.
They replied that in order to maintain low prices of the products, they had to add shipping and "handling" costs to the invoice.
What? They would pull two little brushes off a shelf, out of a box, slip them into a bubble pack and off they went.
I informed them that since I was in the business world, knew what their normal profit margins should be, and to add aprx $10 plus for the products was not in my best interest.
I later bought the same brushes, and $80 of other products from another supplier, with shipping of $12.
They were honest, they had the business volume base to keep cost of shipping down, IE. they were smart, not greedy.
A small detail product supplier is caught in a bad situation today.
Think about it, "why be in business, all the headaches", if you don't make a profit.
Flipping burgers at Mickey D's could be more profitable today.
OK that's my rant.
Grumpy