Your said culture also exists at ebay, not only in Hong Kong.
Two months ago I was liquidating my Manure replicas at ebay and attracted a Malaysian who seek info. (price, provenance, conditions in terms of %-new, names & numbers details, sizes etc.) on the player shirts. He sent discretely 20 e-mails asking the shirts one by one which I answer them all.
At the end, he gave me a list of 12 shirts he wanted and he said he could afford to pay US$100-150 per shirt from me. The price tag of US$100-150 also fixes on the likes of Robson Testimonial, Lace-up 92-94 L/S, Newton Heath L/S and Old Trafford L/S etc. He even said he was very serious and want to buy them off in a single batch, and thus refrained me from selling them elsewhere.
Just ask Uncle Frankie once said - thousands kinda people are nurtured by one kinda rice. Just let it be.