First things first, I don’t think this is a dupe. I’m quite picky about my dupes. Regardless of the discrepancies in formula, I don’t find these to be close enough in color. You can immediately tell these apart in the swatches below. Here are my thoughts on e.l.f. St. Lucia Kit vs. NARS Orgasm/Laguna Blush/Bronzer Duo:
Texture: both are soft but the e.l.f. kit is more powdery
Longevity: the NARS powders last longer on the face
Pigmentation: both are nicely pigmented
Blendability: both are easy to blend
Similarity: Surprisingly, the e.l.f. bronzer is darker. The gold shimmer in NARS Laguna is more noticeable. The e.l.f. blush is less pink and the shimmer in NARS Orgasm is much more pronounced.
In summary: I don’t think the e.l.f. Contouring Kit is a dupe for NARS Orgasm/Laguna, the differences are pretty clear specially if you’ve used NARS’s version before. However, the Contouring Kit is a nice product on its own accord. You might prefer one over the other depending on how much shimmer you want or how dark you need your bronzer to be. Like I mentioned before, the e.l.f. kit feels a bit more powdery and doesn’t last as long but the kit only costs $3 vs. $45 for the NARS duo (or $24 for the mini version).