I heard from one person who bought a house with their pizza bitcoins, indirectly, by trading it for cash first. Apparently it was a lot of hassle with the bank due to AML and just their general distaste for currencies they don't control. I wish I could say I did the same, but the pizza didn't appreciate the same way as the bitcoins 
I think pizza always appreciates. @Laszlo your pizza sorry was the first story I read about bitcoins and my first knowledge of cryptocurrencies, your a legend.The pizzia story is epic.
It really puts into perspective the power of bitcoin.
You can ignore the fact as to how expensive the pizza was, but remember the fact as to how quickly funds were able to be transferred across the atlantic for a specific product.