As I'm sure someone has already noted, LAMY 'Dark Lilac' was a limited edition ink--there wasn't meant to be a second batch.
I had a bottle of the ink, tried it with a dip nib and while it was a nice hue with lots of sheen, I didn't care for the color overall. Not wanting to keep inks that did not appeal to me (even to complete a set) I gave it away to a fellow FPN member.
Personally, I don't believe you missed out on anything special. There are other purple inks out there that are more readily available than LAMY 'Dark Lilac' which are not being sold at inflated prices.
I have some & like it a lot. But a pen pal missed out so I had a go at making a replica for her. Turned out it was quite simple to do, using Iroshizuku Yama-budo + Shin-Kai. It is so similar I can barely detect any difference. It even has the same gold sheen.
Edited by migo984, 13 April 2018 - 19:05.