I am trying to build a PBN. There are services that sell high PA tumblr blogs or high DA wordpress sites. However, when I conduct research on the domains, many of them have N/A for CF and TF. So, what metrics should I look for when buying these types of sites? Should I look for ones that have high DA or PA only and not worry about CF and TF? or look for sites that have both high DA and PA as well as CF and TF? I can get 10 tumblr blogs with PA 27+ but I am not sure if they are actually crap. thanks!