Are Black & Gold and other brands really cheaper?

The last couple of times my husband went to the shop to finalise some details on our fortnightly spending, actually one was our afternoon tea, pre shopping day I think, we have a couple of days overlap. He found the biscuits I think, Arnotts cheaper than the cheap ones, and today the Saxa salt was cheaper than the Black & Gold.

So here is the question? If you buy some or all your things plain label, do you check the price or just throw it in the trolley? Do you think they were just hurrying up the older stock because it was a smaller shop than say Coles? Or do you think you just have to be on your toes, as they are getting quite a few cents more out of you if you don't check the price.