Keep on eye on Google Express: Last week I was going to buy via Google Express:
Kirkland Laundry Soap $16.29
Bounty White Paper Towels $23.54
At the Costco Warehouse the prices for the above items:
$10.99
$15.99
As I recall, the two items were on sale at the Costco Warehouse, but were not on sale going through Google Express.
Same with Amazon, their prices don't always reflect the in-store discounts but that's OK as it still saves me from long lines and the inconvenience of driving to the store and dealing with people