Paying extra for cosmetics isn't for me.
You don't do that with the original sales price from Brompton. With every single special edition since they started doing them in 2011 oder 2012, if I remember correctly, the special edition bikes have not been more expensive as their normal silblings plus the price for the additional extras like special saddle or bags, when you split the prices down. The custom paint job was for free as was the sometimes special bag design. This may have changed a bit with the recent 2020 CHPT3 as at least in Germany it seemed expensive to me - something around 2.700-2.800 AFAIR - a bit steep for a S6Ex with a bag. The bag alone was shortly listed on Brompton's web page for around 80GBP but gone quickly.
So it is basically the guys offering for speculative prices that make a fortune and the demand seems mainly to come from Asia from what dealers tell me. During the first years you could easily grab a special addition from a Brompton dealer for the normal price or even below and even with a year of delay as they did not sell too well back then. This has only changed relatively recently with the massive peak being started with the Explore and now the CHPT3. Brompton has become way more popular and though the production numbers for special editions are massively higher than they used to be they sell out quickly. Now even older special editions pop up with a phantasy price tag on
ebay. I do have my doubts that many sell at those prices given how many are on sale and for how long they are listed.