When I first Deborah Lippmann Mermaid's Dream I was intrigued. I was not intrigued enough to pay $18 for it though. I was really excited to hear that dupe was discovered at Urban Outfitters. I stalked the store for a bit, and it took me awhile to find it, but I eventually did! They sell their polishes 2 for $8, so $4 vs. $18. It's a no brainer.
Sea Dust is a seafoam green foil with small bright blue hex glitters mixed in.
This is certainly a unique polish as far as finish and appearance. I was worried with this polish that it would be gritty as far as texture. I find that the foil finish of this and how the light reflects off those particles gives it the appearance of having texture. This was actually smooth on the nail. I love these colors, and I'm glad I found this alternative polish! I don't think they're exact dupes, but they're pretty darn close. You can find a comparison on Mara in Polishland.