Things I think you should be suspicious of:  Red stitching or writing, says Flair instead of flare, poor quality distressing/fading.

I have five Authentic pairs and three out of the five pairs are different styles. They are all from trusted retailers,  purchased by me from Nordstroms, Neiman Marcus, and Revolve.com. All of the jeans have blue tags with orange and yellow writing. Also all the jeans have mostly orange with some yellow stitching. (I see a lot of jeans on Ebay with red stitching, like on the H on the back pocket) None of my authentic pairs have red stitching or writing.

Also the back of the buttons can say either Corbax Original or have an "H". Four out of five of my jeans have Corbax original and one has the H.

Both pairs of my Ingrids say flare NOT flair. I see a lot of jeans on Ebay with Red stitching and the inside label will say flair instead of flare.

This is info from my authentic pairs, none of which were purchased from Ebay. I just thought I would share some "real" info directly from the pairs I own.

So,  I have told you about my Authentic pairs. And about some things I think are "strange" about pairs for sale on Ebay.  The information I have about my own store bought jeans is the only info I will go by. Hope it helps you too!