some guy on ali has listed a bunch of models including 1080ti for 150 each. hes in uae so its prolly a scam. he has 1000 available so maybe they are stolen from the shipping container.
If you've got the knowledge to steal GPUs from a container you probably also know how much they cost, 100% scam as you said. They're probably not even stolen and it's just a plain scam.It would be very interesting to know what will be the cost of video cards rx580 by piece and if purchased wholesale. Could you then unsubscribe as you will know... 
If you ask around here you'll find the price pretty quickly. You can even just contact manufacturers like MSI and they'll send you their bulk prices.