Welcome to WebmasterWorld wildwill
I've read your post several times but still confused as to what you are asking or require!
You have several names, some are used for real websites and some are parked, correct?
Does each client live website have their own hosting or do you provide it?
If you provide the hosting do you have a reseller account? For insstance I can host as many sites as I like and never get anywhere near my bandwidth allowance for about USD 60 per month.
USD 10 a year for .coms is ok, what's the question?
What is it that you want to do?
Am I missing something simple?