What next - jumble-sale police?

If I have something you want, and you are prepared to pay the price I ask for it, what's wrong with that? That's the basis of commerce. So why should tickets to shows or sporting events be treated any different? And yet, that is what is under discussion at present. There's a serious suggestion that selling on such tickets should be made illegal. Indeed, it already is as regards tickets to football matches - the justification being the need to ensure rival fans are segregated - and apparently it will be as regards tickets to the 2012 Olympics, although the justification for that is far from clear. But it seems to me a dangerous road to go down. Just where do you stop? Like I say, if I've got something you want, and we can agree a price, why should the law interfere?