Where to find cheap domain names?

If you are into internet business or marketing. You of course will have to buy not 1 or 2 domain names but maybe 10 or more domain names.

You won't spend your hard earned money just to purchase a name, will you? After all, it is just a name. So why spend more?

Below are some cheap domain name services that I've found so far. Maybe you can add more if you have any.

godaddy
namecheap

Both offer less than $10/yr per domain name.