They're not difficult, but they are expensive. Which is what ends up in prices.

Check warehouse rates or spot freight shipping.

It is not as silly as it sounds. I am working for a big manufacturer (of products that don't require any spare parts) and the warehouse space is minimal, sometimes raw materials from the suppliers are unpacked and weighted directly on the production line, not going through any warehouse; the finished products are wrapped at the end of the line and loaded directly in the trucks, not going in a local warehouse.

That means if a new requirement appears to add something in the warehouse, space needs to be added. In some cases space does not exist around the plant, so you need to get some space in a warehouse somewhere else, most probably managed by a third party with higher costs, then integrate an inventory management software with that third party warehouse. This is already very complex for a manufacturing plant with zero budget for IT projects and the cheapest IT people needed to keep the lights on.