> but the question remains: are the CPU cycles you spend "mining" for
> Bitcoins worth the value of the Bitcoins you receive?
Of course not. The value of any currency (at a very high level) depends on 2 factors: how much does it cost to get it, and how much do you/others actually want to get it. If these two factors go out of balance (in your example, it is cheaper to create money than to buy it -> it costs less than what people want to pay for it), you can arbitrage that difference and make money "for free" by creating coins and selling them. In fact, that is what several governments have done (because they are the only ones allowed to print money), search for what is called Seigniorage. In the Bitcoin case, where nobody has the power to mint extra coins, the arbitrage possibility is lost, which means that it must be more expensive (or at least the same) to produce a coin than to buy it.
That's why you don't see much people trying to print money and instead trade money for their services: it costs too much to produce (plus risk of getting caught).