Cymbals arent cheap per se, but relative to other instruments they are. A professional saxophone is on the order of $7000 to $20,000. A professional violin can easily be $50,000 and sought after violin's as high as $20 million. Zildjian cymbals for a few hundred dollars are one of the few places a random beginner can consider buying the same instrument used by world level talent.

1 cymbal isn't the instrument though. You're buying a drum set (5 drums typically), a handful of cymbals, stands, etc.

It's also generally accessible to get the same <guitars, bass guitars, keyboards> used by professional musicians. "Concert instruments" less so yes

Its a very high end cymbal hand made, I would expect like at least 600 for a 20" ride. 400 is standard cost for a mass made 20"

I guess not shockingly inexpensive, but seems like a prerty damn good deal