I want to start no argument, but i do want to share my opinion:
I do not find their ink (standard anyhow) to be expensive... its $20 ish for 60ml of ink
Their limited edition is on the more expensive side: ~$35 for 50ml
And their top ink is HUGELY expensive.. at ~$80 per bottle.
As for their quality, i find it behaves better on most pens and papers than say... Pilot Iroshizuku and many noodlers and diamine. i have used no less than 10? 15? full bottles of ink on thousands of pages and so far i like em.
Again, just my opinion and experience