welcomeback
I had just run out of my last 10lb bag of whey (took me just over a year) and went looking for a new one to replace it.
The general price point that I can find for this specific brand/size combination is $159.99 excluding shipping or thereabouts (some places may offer this price with an additional freebie).
The way the deal works is that for spending >$150 you get a freebie; in your checkout cart you can select FREE SHIPPING as the freebie. Then when paying, apply the promo code which takes 15% off and adds a Nutrition Warehouse 400mL Mini Shaker.
Thought this was quite a bargain considering I paid about $170 for my last bag. As of posting all flavours are available. This deal should work with smaller bags as well. My personal favourite is Extreme Milk Chocolate; after two years I still haven't gotten sick of it.
I'm not sure if this is the right place for it, but if you're new to AminoZ (I don't work for them, I just used them recently and it was pretty good), you can get a 20% off code (you have to use it within like 24 hours I think) @ http://www.aminoz.com.au/, they have the same bag of 10lb Optimum Nutrition Gold (I prefer nano stuff normally to micronised, but it's literally the same advertised) for $158.95. With 20% off that comes to $127.16 (free shipping included).