Darkcoin has been in the Keiser Report and he thinks "Darkcoin should be 25% of your crypto portfolio". I think you should go higher than that, but it seems like a good start 
https://www.rt.com/shows/keiser-report/161532-episode-max-keiser-606/
https://www.rt.com/shows/keiser-report/161532-episode-max-keiser-606/