Welcome to cruise-chat.
I rarely endorse drink packages since they usually have lots of caveats and they are designed so as to favor the cruise line. But for a longer voyage such as yours, I do think you may find the lunch and dinner package a convenience.
I don't have a price list. It is common for cruise line drink prices to be in the same range as other lines. I'd look for beer to be 3 to 4 Euros, cocktails and wine to be 5 to 7 Euros. Bottled water and sodas to be 1 to 2 Euros. Perhaps a little less than what I quoted.