Another answer to the original post:
I bought my servers, and co-locate them. I also use H-Sphere.
For a 1 server H-sphere setup with the servers I purchased in a 1 server setup.
1 1U server - $835
12 months of Co-Location @ $150/mo for 1U with my co-lo provider - $1800
H-sphere - $4.50 per account, one time fee for licensing, unlimited servers. Account licenses are recycleable.
$835 + $1800 = $2635 / 12 = ~$220/mo for first year, $150/mo for every consecutive year.
H-sphere licenses are purchased in blocks of 100, so a $450 investment up front is needed, but the licenses are per account with a 1 time fee. So if I host www.somesite.com
and they leave me for some reason, I can use their account license to host www.someoneelse.com.
Licenses are per H-sphere account, and an account can have unlimited emails, and unlimited domains.
I much prefer H-sphere's licensing over Cpanels because this is a standard expense per customer, and I can loadbalance my servers better. I can have 50 customers on 1 server, and 150 on another, and customers cost me $4.50/ea in licensing. Where with cpanel and their $599/year license for 1 server, a 50 user server would be $11.98 per customer per year in licensing, and the 150 user server would be $3.99 per customer per year in licensing.