Amazon has PP 0w20
for $5 a quart or $4.25 through Subscribe and Save program (over 5 items). There is also a $0.40 off coupon per quart on the product page and $2 rebate.
It works out to about $1.85 per quart for me.
Note, if you need less than 5 quarts and don't use S&S, this is an add-on item. So it will ship free with a "qualified order". Or you can probably order it using Alexa and there will be no such restriction for getting it shipped free.