Thanks, Martin. 
I'm quite shocked at the price of the "satchel" #30 20 5270.
65 pence seems like a lot for such a small part.
You're right, I hadn't gone through in detail yet but that doesn't seem right, especially as the same part in dark brown 30 08 0060 was only 13p. I'll question that, and might get a refund. I'll let you know what happens. If I do get a refund, you'll have saved me £5.20.
Those satchels are destined for dressing up US Civil war troopers, to carry their ammunition.
The 30 23 3160 silver hubcaps were only 3p each though, for dressing up my SWAT cars which came with ugly yellow hubcaps - though I've got a feeling they come in pairs, as I seem to have 32 and only needed 16.
I'm shocked by the length of the order - 5 pages !!! The most I ever ordered was 2 pages ...
Bogro
It was actually two orders, but they arrived on the same day.

Some things require multiple parts to assemble - e.g. a winch has 5 parts including the rope with hook, and a spotlight for a helicopter or SWAT vehicle is three parts. To finish some wetsuit divers I needed flippers, aqualung, mask, aqualung hose and aqualung vest.
EDIT:
Got the answer back from Caroline at the UK office already:
"Dear Martin, I have looked into your query, the reason is because they are made in different places and made from different plastics, also the prices are set in Germany we do not price here. Hope this helps , kind regards caroline."
So not quite a £5.20 refund, but at least an explanation.