I think it depends on what you are trying to achive, even as PR4 you should be charging if you wish, I have PR5 directory that is free and I have another directory with lower PR that is NOT free.

nice directory, i have submitted one.

Thanks for you support all.

Submissions have been approved

I submitted a site

Thanks

Nice clean directory. Thanx for adding my listings

thanks, I submitted to the music section.