They are selling a lot of domain names. And must earn a lot.You can say.its like Dollar store. Sale more+small profit= A lot of $$$$$$
Registars buy domains at $6.62 = $6.42 to Verisign and 20 cents to ICANN. If they sell at $9.29 (ie Namecheap) thats $2.67 gross per domain less their expenses (employees, systems, overhead....)
It varies but typically more, often much more, than .coms. Each country's registry sets it's own price.