What are the chances that we find a striker who actually has better numbers than Giroud? Costa is off the market, and I highly doubt that Falcao/Cavani will be moving. So whoever we find will need to give us something different to Giroud (e.g., he gives us speed while playing in place of Giroud, or he can play off Giroud the way Ramsey does).
Balotelli gives us that more direct, more powerful option and great depth at the 9. And if he flops... he'll still do better than Sanogo, Park and Bendnter combined