Costco in Medford, OR (Home) had a case which totalled out to $3.99 per quart. Target was underselling that by approximately a quarter per quart. I'm in Utah now, so not sure where the deal is yet. Mind you, this is all 10W-30 M1.
Target usually has M1 for cheaper than Wallyworld where I am from in Oregon. Last time I bought it there it was under $4 a quart for 10W-30. The jug is still cheaper at Wallyworld, but Target is a good alternative.