What is a typical cost for renter's insurance?

And which companies do you recommend? My car insurance agent is recommending I switch to Penn National and tack on a renter's insurance plan with the following terms:

$21.25/mo
$30k personal property coverage (more than enough for me)
$500k personal liability
and various other coverages.

$21.25/mo doesn't sound like much on the surface, but I've had renter's insurance before that was more like $13-14/mo a few years ago. I'm told the above is Penn National's cheapest option. Thoughts?