My favorite place to buy gold stocks is when gold gets down to its 40 week moving average. But I already own quite a bit of NEM and am not in any particular hurry to add more. However, if I didn't own any at all I would probably be more eager to get in.
The area around the lows so far today may serve as pretty good support - the September closing high, around 42.40 or so. Below that, I would say the area around the rising 20 day EMA (41.77) would be a logical entry price. And below that the area around the 50 day SMA (40.14) has been a very good entry level in the past.
My style would be to have multiple entries - buy a little at the first level and be prepared to add at other levels. But that all depends on your time frame, how tight you want your stops to be, and a bunch of other factors.
Larry