I tried shopping online using the portals and noticed that Sao and Salada are 7-8 cents a piece more at Coles than at Woolworths.
In fact I remember going to the store and seeing Sao for $2.50 each only three or four years ago ($2 when discounted). I haven't really noticed the inflation on these products, but I guess it is rising around 2-3% each year.
Is Coles just more expensive in general when there aren't specials?
Keep in mind the regular prices online are usually 7-9% higher than in store prices (specials and everyday low price type items are the same price online as in store however).
Certain items are often slightly more expensive at one retailer than another with Coles & Woolworths, but overall the price comparisons I've seen show that there isn't much/any difference between the two on an overall shop.