Nothing is too expensive for a digital item.  The only thing that matters is the market cap, and the market cap for Bitcoin is obviously much lower than the value of any fiat currency. 

What people don't understand is that the value of virtual items is just whatever people give them.  Online fiat spending is still just numbers on a screen, what matters is what it represents.  Fiat currencies aren't always even backed up by gold anymore - in the UK, for example, there are far less gold reserves than before, but this has not automatically resulted in inflation.