What is the benefit of buying an expensive IEM if it uses the same drivers as a cheaper one?

For example, in this example we have the Fiio FH3 from 5 years ago and the newer Ziigaat Arcadia. The Fiio costs $100 and the Ziigaat costs $200. Both uses a 10mm DD driver for the bass and then 2x Knowles BA drivers for the mids and the highs (same model numbers as well). Tuning is similar. What makes the Ziigaat cost twice as much? Sorry I'm a noob.