Price controls aren't really a Socialist policy - the Socialist policy in this case would be the gradual change from the production of commodities to the production only of use-values, lacking their exchange value dimension. If price controls are a Socialist policy, then it doesn't take much for Socialism to come about - but that's clearly not what Socialists are talking about when they talk about Socialist policy. Marx, for one, wasn't in favour of price controls to my knowledge. Nor were the other Socialist economists and theorists. I'm not sure where you're getting the idea from other than the oft-repeated myth that Socialism is merely when the government "does stuff".