@OptOut: I can understand those who keep information to themselves, I'd think that this would generally be more common until people find and obtain the item in question, who wants to create more competition for him or her self?
@Everyone: Taiwanese collectors and Thai collectors are this way. I have seen some pictures of friends' collections, where they have thirty or so of the same item. In their mindset, if they have a lot, it is proof they like the thing.
I personally generally don't collect more than one, though there are a few exceptions, which sometimes relate to me feeling a product is undervalued.