Unless you can afford a few hundred dollars a year for .com .net and .org selling license, and then anotherlump sump for all the other domains, then I suggest going with another registrar. I use
http://www.enom.com http://www.123-reg.co.co.uk and
http://www.xreg.co.uk
Using a 3rd party to register the domains will work out alot cheaper, as you'd need to sell hundreds of domains to get your money back from the licences, and there's no way you can fit all those onto a single server