The admin interface is out of this world!
(designed by ravio)
www.perlbill.com is where its from. Its $199 which is cheap compared with a few other scripts. The developers release updates often and are available on messengers.
Its good for any sort of sales/support not just hosting!
There is a demo on the perlbill site. We are doing some modifications and testing on our install of it before we let customers use it
Regards,
Matt