Diapers are something you want to stock up on when you see a good deal.
A good stock up price is 10 cents a diaper.
I'm not in this stage of parenting anymore so I have no idea what Safeway usually charges for diapers.
Do your homework and check the flyers for local deals, and don't forget that food banks are always looking for donations as well.
You can simply show this coupon on your phone to the cashier to use.