Online Sellers; How Authentic is Authentic?

Since late last year, I've been dreaming to have my own Longchamp Neo, I already have two Le Pliage but when the Neo came out I said I wanted one but I find it so expensive when I checked it out in Rustan's. So anyways I've been searching on Instagram who sells Longchamps and I was surprised that there are a lot of sellers, even on Facebook! And every single one claims that it is "Authentic" and I was like really? I saw one who admits that her products are Class A and another one who offers money back guarantee if proven to be fake. But what about the others who claim they are authentic, and what does authentic really means now for online sellers and consumers?

How authentic is authentic nowadays? Now I am more confused, I assume an original Longchamp Neo runs maybe from Php8,000 and up (mine was a gift/pasalubong from relatives who came from Europe so I don't have any idea how much was the Le Pliage before) so anyways, from 8K down to online sellers of like Php2,000 and even Php3,000 buy 1 get 1 so that's Php1,500 I am now shaking my head. Is there any law protecting the rights of the consumers who buy online? There are also sellers who indicates "no return/exchange policy, no cancellations, buy at your own risk, and even no COD" if you say your products are authentic you have to back it up right? So sorry for all the questions, it just frustrates me that these sellers sell them with those prices but couldn't actually stand for their products quality or authenticity. Oh another thing, when they say factory overruns, really again? do you think Longchamp, Beaachkins, MK, and other branded bags would deliberately allow to have  thousands of factory defected products during production and in all colors pa? I assume their quality control areas are super strict in implementing high quality production control. They are selling too many of these "authentic products" that in my opinion are still expensive, if they are fake they should be sold at less than a thousand, than claim to be authentic and sell at 2K and up is just unfair for both the brand and the consumers right?

Oh well, I don't know how to end this post right now, I just want to share my opinion... feel free to share yours on the comment section :-)