berlinonaut

Where is "here"? I would not say all the stock Brompton parts are quite crappy. I own a couple of Bromptons of different ages and the quality of the parts has improved a lot over time. And they do the job. No doubt there are parts of higher quality available (especially in terms of bling and weight) but for a price. And typically not only for a financial price but sometimes also in terms of endurance or limitations in use. As many of the aftermarket parts come from Asia they are not only more expensive in Europe but sometimes also designed with an asian rider in mind (smaller size and less weight on average) which may limit the usefulness for taller or heavier Europeans or Americans sometimes. Maybe that's the reason why there seems i.e. to be no aftermarket titanium telescopic seatpost available while the amount of aftermarket ti seatposts for the Brompton has risen to probably more of a dozen over the last years.

So to me the stock parts still are a good compromise for everyday use in even harsh conditions with a good lifespan whereas some of the amazing looking tuning bikes seem more like showroom bikes to me. Nothing wrong about that, just not my cup of tea - my Bromptons are workhorses. Still thankful for some of the aftermarket upgrade possibilities. The whole aftermarket business has only evolved in the last years - in ~2011 Brompfication was founded. Before them there was Kamoya (who did not ship outside Japan), Steve Parry, Ben Cooper, Juliane Neuss and maybe Mr. Ultimate Folding Bike (who all did Brompton tuning but not in the sense of bling and accessories that we see today). That was pretty much about it. Most of the other companies appeared only over the last years with the Brompton becoming popular in Asia (and Brompton tuning becoming popular along with it as well).
Here in Europe the resale value of original parts is pretty much ok btw..