Hmm. I am divided on this product. For one thing, the color selection (compared to other concealers) is very good. I would say only a few other companies have this varied of a selection of color choices for concealer (the foremost being of course MAC).
The "standard" colors that you find in the store are Ivoire, Correcteur, Light Buff, Clair II, Camee, Medium Bisque, and in rare cases, Caramel. However, on lancome.com it lists four more shades: Honey and Dore (which come between Medium Bisque & Caramel), and Bronze and Suede (which come last, after Caramel). It made me pretty angry that most retailers don't offer these darker shades (and if you read any of my reviews, you would know why! :o) ) I happen to be very slightly darker than Dore (around NC40-NC42 in MAC), when I finally found a tester in a Macy's that offered Dore. However, since I found the shade for $10 on ebay, I figured I would just buy it. Big mistake! I should have bought from Macy's so I could return it. Anyway . . .
About the actual concealer: I like thick coverage of my horrendous purple under-eyes circles, but I had to layer it on to get adequate coverage. Complete coverage, my butt! And it's not very long-lasting. After a couple hours, the color had mostly faded away. So I reapplied again, right before yoga (yes, I wear concealer during exercise! I am one of those girls). BIG mistake. I was used to my Cover FX foundation with powder on top lasting pretty well through a very sweaty yoga session. The maquicomplet concealer (with a bunch of powder on top!) melted under my eyes and it looked like I had been crying (when I looked at myself in the mirror after yoga). To be fair, the concealer doesn't claim to be waterproof, but I'm afraid to wear it and go out in a light drizzle.
As to the price, I can't really comment too much on that. The list price is around 29 dollars, which I think is a bit too much for the amount of product you get (0.25 oz, which is not too bad). However I got it on eBay for 10 dollars. I would recommend testing the product at a Macy's or other retailer, and making sure you like it, and then purchasing it for much less online.