I'm not talking about directory submissions or outsourcing articles and then article submissions. Frankly I think that Google gives extremely low link juice coming from article and link directories (except DMOZ, of course). So if you have some $$$ to spend, what do you think is the most efficient method, in terms of "link juice per $ spent"? Interested to hear your views.
If I have $$$ to spend, I won't just go about purchasing links. I'll just use the money to invest in getting quality articles to submit to my blog and part of the extract from selected articles will be used for submit to article directories with the links there. I know you mentioned here that they give low link juice but frankly I think it is still better than going for paid links.
It depends on your niche. Check what your top competitors are doing. See if you can copy some of their links. It is best to use a balanced strategy using multiple techniques. That way if one of the techniques becomes less beneficial then you still have your other techniques to fall back on. Paid text links may be tempting, but they are being targeted by Google and may become a lot less effective very soon. So it may not be worth going that route. I would recommend hiring some freelance employees from either elance.com or rentacoder.com. Get them to write you some articles and submit them on various article directories. Also pay someone to regularly add fresh content to your website.