Depends completely on the trading price. There are 5 million GPUs in the world being used for mining. Eth is netting about $4.5M per day and makes up for majority of GPU profits. You could look at about $7-7.5M per day combined across all GPU algos, which more or less corresponds to average of slightly more than $1 per cheap card.
BTC Gold would produce 1800 coins per day. 1800 * BTC Gold price = however much more money left for miners. If it's traded for $1000, that's almost $2M and is quite a lot. If it's traded at $100, it will be well within daily fluctuations of what we have right now.