I've never spent just $5 on a Fiverr job. Example: if you want someone to design you a logo the $5 will get you a low res one but you'll have to pay another $40 to get the PSD files and revisions.
With that said, I've had some great experience with it hiring creative types.
Yeah, the base price is $5 and you can pay in multiples of $5 for slightly more complex things. Basically people will do very simple work for $5 or a multiple thereof.