So do you want a quart to be 1/5 the price of a 5 qt jug, to the penny?
Do what's mentioned above, refill a quart bottle.
I think the biggest price matching conundrum would be trying to do it to a "5 qt plus filter oil change deal" and/or lining up the brands to match exactly.
Note, parts stores that aren't WM carry 5.1 qt jugs so there will be no cross price matching there.