A Mercedes 200 CDI or a 220 CDI?

I had long been hesitating between a Mercedes C200 CDI and a C220 CDI. When I took some advice, I realised that the only difference was the programming of the injection. So I went for the smaller version with a box-unit from you. Instead of paying 2,200 Euros for the larger version, I only spent 530 and the result is the same.�  

Carlo W., Luxembourg.