I agree that posting and packing are always going to be a factor. The other points you mention are becoming less relevant as we move towards online buying. Thi

I agree that posting and packing are always going to be a factor. The other points you mention are becoming less relevant as we move towards online buying. This is especially true of shops selling random obscure parts. Also, just think about how annoying normal 2d printers are. Sure you can print something at home; but it will be expensive and slow compared with the expensive laser printer at the office.