Priming a dunkelweizen

So I'm getting ready to prime a dunkelweizen and I've come across the tastybrew priming calculator. Based on that, it's saying I need to use 8 oz of table sugar for a 5 gallon batch! That amount just seems so high compared to what I've used in the past. Any thoughts on this? I was also thinking of possibly using brown sugar, but would it actually impart flavor when used just for priming? And if I were to use that instead, how much for a 5 gallon batch?