truck wheel rant

I bought my plain Jane 17" winter rims for my 2017 ram from the dealership. $57 each.

its not a ram, though
but i like that price, i might call them monday

so far ive come across one set of "factory take offs" steel, silver painted 18X8s for $350
then add some 265-70-18s for about $600 and mounting and balancing, man, thats a grand
i doubt i will get that back for those stinking dubs

i wonder what weight index tire i would need for a 7000 pound rig?