economatic is NOT same as OE Quick Strut. you can go with cheapest economatics, but those struts are weak and just that economy/budget version.
OE replacement would be a Monroe Quick Strut 171678-171681, like this:
also check
www.rockauto.com and
www.partstrain.com for pricing, besides amazon and advanceauto. it's possible that nowadays advanceauto will come up cheapest with all the discounts you can get (don't rush the order, play with shopping cart, probably separating it into 4 different orders givers best discounts).