I thought I'd do a quick comparison post for you today showing Nars Purple rain and a very close colour to it, in the form of W7 Purple Paradise. I did think a couple of weeks ago that in the bottle they would be dupes but on the nail they are very slightly different.
Tee Dee over at Cute-Tickles has done a lovely post with the W7 Purple Paradise, and I said they were dupes in the comments, which is why I did this post, but lo and behold they aren't, I apologise to anyone who may have thought that they were because of me!
W7's Purple Paradise has a much warmer tone that the Nars Purple Rain which in turn has larger blue shimmer particles and is also much darker round the edges.
From left to right in sunlight - Nars, W7, Nars, W7:
Left - Nars, right - W7 (in sunlight and close up):
Same again at different angle in sunlight:
At this low angle it is harder to tell the difference between them, left to right - Nars, W7, Nars:
Under warm tone bright kitchen spotlight, left to right - Nars, W7, Nars, W7:
In same order in natural light with flash:
In natural light without flash, again same order as previous photos:
In real life the difference is harder to tell than in these photos though, so if you were looking for a cheaper option to the Nars one then why not try the W7, I got mine from Amazon. As far as I know the W7 is not free from formaldehyde, toluene and DBP, whereas the Nars is, so that could be a deciding factor for you.
Hope this has been of use to you! xxx