We do our best knowing we're saving "something" every time we go shopping. It's not always the lowest price we could possibly get but it's still not full retail price.
And we try to save on everything, not just groceries. Our food bill may be one of our biggest budget challenges (have you seen how much 3 boys can eat?

) but if we can save a little bit on "everything" we buy, then I'm happy. Clothes, pet supplies, household goods, phone service, utilities... every little bit helps.
When we get our paychecks and those dollars come marching into our checking account, I like to make sure they're working at least a little bit before they go marching back out.

Some of them could certainly work harder but so long as each one puts in some effort it's a good thing.