>> "If we can tell ​a buyer​ somehow​ that the laptop he is about to buy is stolen, ​there is a high probability that he will not buy it."

I don't think this is true. People buying cheap laptops on the grey/black market care about 1 thing - price. Most know int he back of their minds there is something shady about the deal but it doesn't bother them enough to say no to a low price.