Nope. Most of the comment links are nofollow and if you somehow find a blog that allows you to have do-follow link, it'll invite a lot of spammy comments. Now, let's say the comment section is well moderated and your comment somehow passed-through their check, it'll still not be as powerful as the in-content link. If the main contextual link gets 70 JP, your comment link will get 10 JP and that JP is shared across all the comments with external links. Google's penguin algorithm knows the difference between the contextual links that is within the body of the article and those in the comment section.