There are other costs involved though to consider.
Larger companies will not use old boxes they have lying around, they will buy shipping items like boxes, shipping bags, Jiffy bags, parcel tape, bubble wrap, box stuffing, shipping labels, postage tags,
then they have to pay someone's wages to find the goods, pack the goods, organise the shipping.


They will also choose to use a postage service that they know they can rely on, as the company name is on the line, even if it is more costly, and also insure the goods in case they are lost.

I'm sure they would be happy for you to pop in and pick it up which would prevent any of these costings lol.