beware of imitations

So I bought some "7 for all Mankind" jeans yesterday at the Grand Bazaar in Istanbul. They looked a lot like the real thing - the little grommets say 7 for all Mankind, the tags inside look just like the tags on my for-sure real sevens at home. And the paper tags that say the brand on them looked pretty real too. Even down to the "Beware of Imitations" notice on it. The one thing I forgot to check before I bought was the zipper - they are always by YKK. I got them tailored as well so they don't drag on the ground. And I didn't pay too much for them. Well, now I wish I had paid somewhat less...

Well, I put them on last night and after a few minutes realized i forgot to zip the fly. Only the zipper was broken. Oooops.

So what i want to know is - how do they do this? Do they make them in the same factory, but use cheaper zippers and presumably, cheaper fabric as well? Anyway, I will either go back if I have time and see if they will fix it, or just add a button in instead - the zipper is short, so a button would work.

If you have any theories on how they make jean imitations let me know. I tried googling this but either Google sucks, or no one has written about it.