LOL..Actually buying links is not the problem, Buying Low Quality links can be a problem. So you better opt for building Quality links. I can suggest you Guest post service, High DA posts, Blog comments, Press Releases, Social shares and also few Quality Web 2.0's.
For these services, you need to get some High Quality Native writer's articles, which can bring a good traffic for you. You can also do some Keyword analysis, though which you will get an idea to concentrate on Low Competitive keywords too. good luck.