Just buy BTC, if i had spent all my $ on BTC back in February rather than buy miners... Id have 20x as much in USD.
This is all true but the that's the nature of mining, your risk is picking the horse to back, but you should ultimately do cost calculations taking into account that bitcoin will likely rise as is the nature of bitcoin to do so. I bought my KnC Mercury when bitcoin was £70 and then it went 4x that and as long as it stays reasonably high, I don't see it going less than £140 personally, then I'm easily going to make a decent profit.
I always feel that there's a bit more safety in mining as the hardware is 100% yours but now that it's all ASIC based that's probably not much of a comfort if bitcoin did go wrong in a big way.