200mls of oil sounds a lot to me sals. I just throw a bag of salted roasted peanuts in the bowl and grind on speed 8 until i have the consistency I want. I haven't found I need to add any oil at all.
Randomness, my peanut butter lasts for ages (if my son doesn't find it!); over two months. My attitude is, if it's not green and furry and still tastes/smells good then go ahead and use it.