A LOT, because there is no alternative and the base concept is great and there is a demand.
There is no alternative?? how about litecoins, or Ripples, or any other web currency that may come out
I think you're right. With the success that bitcoins have been seeing, you can guarantee that there will bit other alternatives like litecoin where people might try and just on the bandwagon so they don't 'miss out' on whats happened with BTC over the last year.
I'd rather invest $10 now in some alternative in hopes it gets big, then miss out.