I got the same pair many years ago for just 20€. They were amazing for the price, but sadly the rubber for the earpads and headband got flakey and i wasn’t able to enjoy them anymore… I’m using the HD569 now with replacable cables and earpads, but they are a bit pricey compared to the HD210.

It depends on how you define quality.

• If you define it by general shape and tolerances, 3d printing can(!) achieve a comparable quality.
• if you define it by it’s surface finish, SLA prints can but it’s nearly impossible with FDM (at least currently).
• and if you define it, by its tensile strength or mechanical properties injection molded pieces wil probably always have an edge over 3d prints because of their anisotropic behaviour (meaning the piece can endure forces differently depending on the direction)

And of course as already mentioned injection molding is a much better fit for mass production.