I've very happy about the Bitcoin sale but I think it's better to use fiat to buy mining contracts right now. The current drop in value could easily lead to a drop in transactions. In turn, that's likely to lead to a drop in the mining difficulty. As such, I'm inclined to invest in open-ended Bitcoin mining contracts like those available through Genesis Mining (if they weren't sold out) or this mob in Poland: https://www.ccgmining.com/aff.php?aff=6355