Wish you were my godparent
200 is way too much IMO. Think about it, you have years of birthdays and christmases and easters for this child. If you give 200 for the christening, are you then expected to give the same (or more) for the first birthday...then what do you give for xmas etc etc? Just keep those things in mind!
A bracelet with a charm, or name on it etc, is a lovely gift for a godparent to give. Don't buy 'Christening' picture frames because believe me, the child will get about 50 of them and they will never be used
Being a godparent is not really about giving loads of money, it's more about loving and caring and guiding the child as it gets older (apart from the religious connatations). So a bank account with 50euro (if you want to give cash) and a bracelet (or similar) would be much more suitable. No one would expect that kind of cash for a christening present in this day and age. Enjoy the day btw