SeoForums.org does not condone or encourage the buying or selling of links, these sections exist so that such threads are kept out of the general discussion areas.
You should be absolutely aware of the google guidelines, which prohibit the buying or selling of links to artificially boost pagerank, or search engine positions.
When buying or selling links you should only really be looking at related websites. Put it this way - would you buy advertising space on a particular website? If the answer is YES then you should buy links on it for advertising purposes.
Be Good - Play Safe and you wont get in trouble with Google, Be Spammy and your site will probably be banned, or lose its pagerank.