Buying backlinks - how do you find someone that you trust?

Hi all, i currently have a site with excellent content, but i cant rank for competitive keywords. I think the main reason is because i dont have enough backlinks pointing to my site. I want to grow my backlink profile, but it is a jungle out there. Most people offering PBN's or crappy links. However, my competitors are beating me with these crappy links. Does anyone have any insights or help?