I'm giving you a hypothetical situation where Canada started up an exchange for Fords and offered the currency on the exchange for $0. What would happen? It would float toward the price that the market would bear, which would look like a thousands of percent increase.
The reason the Euro started off there is because, like an IPO, they thought that because an entire federation of countries was backing it, they could offer it initially for a price higher than $0, just like Facebook thought that because millions of people knew what Facebook was they could offer their shares for a higher price than $0. In all likelihood Canada would offer it for a price higher than $0, and the market would probably bear that price.
BitCoin couldn't do that because it wasn't introduced by a federation or a nation. Satoshi couldn't just go to an exchange and offer BitCoins for $600 because nobody had heard of BitCoin and people were skeptical. So it had to make the journey from $0 to $600 on its own.
But now that it has earned the faith of the people who use it, what makes it different from a national currency being offered that price? Not much.
" A currency is defined by liquidity and there just aren't many things you can currently exchange for a bitcoin. "
There are more and more things you can exchange a BitCoin for every single day. And if you're a vendor, don't you want to accept BitCoins? If someone wanted to give me a BitCoin in exchange for something worth say, $550, I would accept it because a BitCoin is worth about that much on the exchange and there's a high chance that it will be worth more tomorrow. It might not make a whole lot of sense to spend BitCoins right now but for the very same reason it makes all the sense in the world to accept them. Vendors have every incentive to accept BitCoins at the moment, which means there will be more and more of them, which means BitCoin's utility as a currency will only go up. Network effects.