It's also worth pointing out that you are probably incurring significant fees when converting from your native currency into bitcoin.
In addition, if you are holding bitcoins with the expectation that they will actually appreciate (i.e. the currency will deflate rather than inflate) you are effectively losing money by spending it, further discouraging you from engaging in the transaction.
Krugman has enjoyed making this point a few times:
http://krugman.blogs.nytimes.com/2013/12/28/bitcoin-is-evil/
http://krugman.blogs.nytimes.com/2011/09/07/golden-cyberfett...