Hopefully this will become a moot point, because the panic buying for most items has peaked and is on the decline. There will probably be waves of new things for a while though.
I'm not sure why this is such a difficult thing to police, but i suppose there are reasons. OTOH eBay's policy's in relation to this have caught me out when I've been trying to do the right thing. e.g. you can't put the full word for CV in an item description; I just get a warning that profiteering won't be tolerated - when all I was trying to do was use the word in a sentence to warn overseas buyers about postage delays. This contirbuted to my decision to ditch overseas selling, though I probably would have done anyway.
