mike writes:
On 24-03-2021 07:40 trader_4 wrote:

$2 a qt? I buy Mobil one there and it's nowhere near that cheap, even when
on sale. As I recall it's more like $25 for six, $4+ a qt.

The normal price of the Kirkland 5W30 API SP synthetic is $2.50/quart
($25/10 quarts) although this lookup just now shows it at $30/10 quarts.
https://www.costco.com/motor-oil.html

Note that costco on-line prices are often much higher
than in-store prices.