I didn't think that 10-30 could be considered "resource conserving".
They are and have been since the beginning of the Starbust:
Mobil Super 10W-30 contains friction-reducing additives. The American Petroleum Institute (API) classifies this viscosity grade (10W-30) as "Resource Conserving" engine lubricants and these viscosity grades meet or exceed ILSAC GF-5 / API SN Plus. Those claims are backward compatible with earlier performance levels such as API SN, SM, SL, and SJ and previous ILSAC categories.
I like the half quart size. Sometimes I am not thirsty enough to drink a whole quart at once. Otherwise it seems like a silly stunt to hit $1 price point and wastes plastic compared to larger containers.
Few days ago Kirkland plus 0W20 and 5W30 box were $20 or $21 at Costco. they were $3 off regular price. That's about $2 /qt. they were displayed right by the main center aisle. Didn't see any 10W30 as you have to go deeper into the aisle and I was trying to get out of there quickly. You know the new co-owner Mr. C19 may not be very friendly
I've also read that in Mexico some fill up Evian bottled spring water with tap water ... So api sn may mean nothing over there. Maybe when it's sold in U.S. it has to be real SN but I would not risk it.
But that doesn't take into account that Costco memberships aren't free. A more fair comparison is Walmart Supertech synthetic for $15 per 5qts, or in these parts Menards FVP full Synthetic for $3/qt for individual quarts.
You CAN purchase from Costco without a membership but a 5% surcharge will be added. It's also been mentioned here that you can use the pharmacy without a membership because of state laws. So the Supertech may still not be the best value.
Non-Members Can Purchase from Costco.com
Non-members can purchase from Costco's website, Costco.com, at any time. There is a downside, however:
"If you are not a member, you will be charged a 5% surcharge over posted prices for members (except for prescription drugs). This is because our ability to offer low prices on brand-name items is due in large part to our membership program, which is designed to reward members for their loyalty."