I bought nine 5L jugs of Castrol Edge 5w30 Full Synthetic for about $9 CAD per jug shipped to my home when walmart had a price error/clear out online. D1G2, SN+
It was worth it. I do oil changes every 3.5K miles. So with a filter, o-ring, and doing it myself, it works out to about $20 CAD to do an oil change.
Usually the same oil is regular price for about $60 CAD, and about half of that when on sale.
Too good a deal to pass up on.