For fun, you can read the various agreements.
Get started: (please notice updated prices!)
You can also manage existing domains at OpenSRS directly.
We do not do this for profit; we do this as a service for friends, acquaintances, and co-workers. All of this comes out of our pockets. We are not a business, nor do we want to be (which is why we do not take credit cards -- we want neither the hassle nor the responsibility of handling your financial data.)
How this works:
If you want to tack on a little extra for infrastructure costs we certainly won't complain. Our Paypal address is email@example.com. (paypal also skims 2.9% + 30c per receiving transaction - ($0.59 out of $10))
You may also send antiquated paper checks to the contact address for sackheads.org as listed in the WHOIS database if you absolutely must, but please send an email saying that you have done so.