5$ they're just a proxy for some public ftp mp3 index, using grooveshark name and style to bootstrap visits.
According to this tweet[1] it's actually mp3juices.se with a different skin. That seems to be confirmed by the same habit of using dl.<domain> for media serving, the very similar layout, and the same (apparent) choice of hosting provider.
Also, how is this running with that feature? Is this hosted on the moon?