It depends on which page that you think is the most important. But If you can afford to do so I would buy links for both.
OK so I can google or search for links references but has anyone got any good sources of links brokerages?
I think it's best to link your homepage with 40 percent of links and inner pages with something around 60 percent. Google doesn't like it if you link only one page with one keywords. It's unnatural ;-)