The difference is that the Raleigh NOS parts are no longer available so I can see why some restorers will pay so much for that perfect last bit of detail. I have a NOS 1992 Honda Fireblade rear plastic mudguard assembly in the box and that is probably worth about £500 😮 as you won’t be able to buy another, I have also got a complete NOS tool kit, all sealed in the bags, again someone will pay a crazy amount of money for that last bit of detail.
However the Brompton parts on
eBay are just taking the Michael, A Brompton dealer I deal with told me that they have a customer who buys about £200 of stock a week and just lists it all on eBay and Amazon at a premium. Every genuine Brompton part I’ve seen listed on eBay or Amazon is more expensive than buying direct from Brompton or their dealers.