Find reseller or master, or alpha reseller [required with free whmcs monthly fee 7-10 If so, contact. Or reply.
WHMCS costs $10-15/month (depending on volume) and ClientExec costs around the same amount. I don't think you will find free WHMCS/ClientExec at that budget.
http://forums.digitalpoint.com/showthread.php?t=1755947 Reseller UNLIMITED (5 Available) Unmetered RAID Protected Disk Space Unmetered GB Premium Multi-Homed Bandwidth Unlimited cPanel Accounts WebHostManager (WHM) included PHP 5, CGI, Perl, cURL, MySQL, MySQLi, GD Library, Zend and more... 99.9% Uptime Guarantee FREE Enom Domain Reselling Account or ResellerClub/DirectI Domain Reselling Account **FREE WHMCS** $10.13 USD Monthly I am thinking to enjoy their service however,I want to try,may be have more cheap than them!
I can offer you reseller account with free whmcs and a domain(already registered) for a one-time payment, $50. cPanel/WHM 99.9% uptime and premium features.
Please check out my Post: http://forums.digitalpoint.com/showthread.php?t=1755510 Billing software (Client Exec/WHMCS Depending on plan) is free for all reseller accounts except for Reseller basic, Which will cost you $9 /Month for Client Exec or $11 /Month for WHMCS.