A Bit About BitCoins

What is a Bitcoin?
Nothing. They don't exist. Not even in the sense you're thinking they do.

Bitcoin is actually a system of recording transactions, and not a unit of currency. Bitcoins do not have serial numbers, are absolutely indistinguishable from each other, and can be broken down into any smaller unit of value without having to exchange one object for another (like a dollar for four quarters). It's important to keep this in mind.

How do I get a Bitcoin?
Again, you don't.

You can create a wallet, which is an address in the system, that can be credited a payment of a certain amount of bitcoins, but you never actually receive a bitcoin. While functionally, you have the authority to spend all the bitcoins that have been credited to the address, so in simple terms, you "have" those bitcoins.

The issue is that the bitcoins cannot be taken from that address. Bitcoin relies on a complicated encryption system that means a transaction must be voluntary (i.e. you must provide the password [actually a private key] to the account for each transaction). That also means if anyone gets your password, they have your bitcoins. There's no such thing as "cold storage" because every address is part of the network at all times.

That being said it's safer to keep your private keys away from machines connected to the internet unless you're authorizing a transaction.

How much are they worth?
Well, as Buffett said, price is what you pay, value is what you get.

Don't be coy. It doesn't suit you.
You are correct imaginary interlocutor, so in an effort to answer your question the only way I know how, here's math.

Bitcoins have a fixed supply, and a fixed velocity. There can be no more than 21 million of them, and each one can trade hands roughly once an hour. (This is not 100% accurate, but for now we'll use it). What that means is that there can be at most 184 billion bitcoins worth of transactions a year.

That sounds like a lot.
No it doesn't. The United States GDP was roughly $16.4 trillion last year and that's about a quarter of the global GDP. That means that each bitcoin is worth roughly $356 2012 USD, if you assume BTC will replace 100% of global currency. Scale to your liking depending on the anticipated adoption rate.

Why is there an extra number there?
Because USD are inflationary, in that more are issued each year. We do this because economics tells us that is how to run a healthy economy. Generally inflation is used to prevent wealth accumulation which prevents trade and destroys economies. Bitcoins, however, are deflationary, in that there's a fixed supply of them.

This is very, very bad. It is also why no country has used a non-fiat currency in decades. That being said, the relationship between USD and Bitcoins is such that the value of a Bitcoin goes up every year, or more precisely, the value of a dollar goes down.

Are there other ways to get Bitcoins?
Yes, you can mine them. In practical terms, you cannot mine them. What you can do is purchase mining power from a commodity exchange like CEX. Mining power is measured in GH/s or billions of equations solved per second.

That sounds confusing.
Indeed.

What are GH/s worth?
Well, to give you the straight dope on that you need to know what today's risk-free rate of return is. If we assume that to be 3%, than a GH/s is worth roughly 13.9 BTC until next year, then it goes down by about 30% every two weeks as the difficulty increases.

Caveat Lector
This is economics, not trading advice
Now, on to the more important caveat. You cannot buy a BTC for $356 USD. You cannot sell a GH/s for 13 BTC. These things exist in thinly traded, ill-informed, wildly volatile and incredibly speculative markets.

The equations above tell you the value, not the price. I make absolutely no prediction as to what the price of any commodity will be at any given time, because "Markets can remain irrational a lot longer than you and I can remain solvent."