There's an absolutely hilarious discussion going on at WebmasterWorld forums (which is probably taken too seriously by some of the participants):
For saving $5 you want to take a chance that a authority site(remember why you linked to it) disavows your link? Don't forget that Google already rewards for outbound linking to good sites.
It's worth going through the whole discussion but keep in mind that I am not the only one who was once threatened to lose my website for linking out to some big site, so the future is almost now! I can see a big guy like that emailing me asking for $5 or they will disavow my link :)
Dear Sir/Madame, It has come to our attention that your website somebusiness. has link out to our website thebestinitsfield. We welcome such links from high quality and respected websites such as yours. In our endeavour to provide the best resource in our field, we routinely screen the websites that use our resource as a reference, because Google has a policy( a link here to Google's blog about disavow links) of penalising sites that are seen to have low quality links to it.Google suspects those low quality links to be bought by the website that they are linking to and thus outside their guidelines to successful ranking. A website such as ours attracts many new links daily and to protect our integrity, which is in your interest and ours, we have come up with a system where quality sites such as yours who link to us, pay a token price of $5 paypal to verify that your link to thebestinitsfield is valid. In this way, we protect both the integrity of your website and ours. Our paypal address is pay-or-disavow @ thebestinitsfield. Please contact us if you have any enquiries.
Thanks to Sean Cohan for emailing me this thread!