Hi , i am a seo Specialist for many years now. I really think that people are sometimes so scared about penalty from Google. meanwhile everyone is busy getting backlinks . It doesn't matter whether you buy them or trade them. I would say read the manual what google has to say about this
Google literally says writes that you have to write good content and if you do your best, someone will automatically link to you. I finished reading very quickly. While every Seo Specialist just knows that you just have to link to reach your position .I would say keep it tidy and take a good Seo Specialist who knows what he is doing and knows where to get his links. You can always ask me if you want .
With kind regards Anthony