I don't know what that particular WM is thinking with that oil. RP is available anywhere cheaper than that. Dave probably would still go to Walmart up here; we do get $6/gallon specials on Supertech occasionally!
I used to use M1 in my truck, and tried QSUD out of curiosity. I found it runs a bit quieter, and cheaper to boot, thus it's my go-to for now (until I get curious again and try something else). It's a great oil for the price imo