Yes but its better you buy a discounted 1 st class ticket. Try
[email protected] ask for Peter and he can sort you out. To pay for C class and then upgrade with cash will be far more expensive than buying a cheap 1st class. You should try buying D class as the only difference is the miles you get and everything else is the same. The chances of a free upgrade are almsot zero - they just dont so it unless massive oversold and you need to be at least gold card holder.