Even if, right now, a Bitcoin can not be produced under $400, it still needs community consensus to stay above that price. A crash to 200$ could happen, and difficulty would adapt so a Bitcoin could be produced at that price. And ASIC companies who have access to cheap miners and electricity can propably produce them at a considerably lower price anyways. Because of this, I think it's wrong to say that PoW gives a base value to a coin.
And there is no way to cheat with PoS either; everybody gets the same interest rate for protecting the network.
I am open to both POW and POS, but POW is working for bitcoin from start, and POS is still young and needs validation over time (in sense of market sentiment and acceptance). Is it worth to improve security with POS but at the same time introduce new (unknown at the time) risk factors?
Many coins have took risks with PoS by now, and no major problem have been found.
Dogecoin's developper consider that using PoS might be a good idea no sooner than the 600000th block, so that's plenty of time for other coins to thoroughly test it really.