I have 5 of the 140 luck robes, but that is because I spent many hours running the quest early on Origin. It would be almost impossible to do the same on other shards as you have too much competition trying to grab up the dungeon essence. Now that more players on Origin are starting to search for essence, it is taking me twice as long. On a low population shard it would normally take about 3 to 4 hours to get enough blue crystals to get a 140 luck robe. On a high population shard it could take a couple days. You need about 50 blue crystals to heal up a gypsy. My advice would be to get your 50 crystals first and don't waste them until you have all 50 - that way you are guaranteed a garb.