at register.com,it’s $35/year for a .com domain.Why it’s so expensive?
they must be still getting enough sign-ups and renewals at that rate to make it profitable for them.
Maybe that’s the first one that comes up on google and people do not shop around?
No idea. I had a client who was using them, and I migrated them over to godaddy.
It’s not like register.com has an out-of-this-world domain management interface that makes it worth the money–I wouldn’t say it’s terrible, but it’s certainly not very good.
Why don’t look at other domain name registrars?
$35 for COM domain name is too much…
Things probably go like this: They’re an old registrar, and have a decently sized customer base used to that pricing. The price means probably something like $25 profit per domain per year. If they were to start competing with the $11 registrars, they would need something like 25 times as many customers as they have now to maintain the same profit levels. Unlikely to happen anytime soon. 
I’ll admit - I still use them from time to time. Why? Simplicity. Seriously, I tried godaddy once, and my head hurt trying to manage my accounts there. It’s just way too messy!
Register.com is expensive, but it’s painfully simple and clean to use. Plus, I tend to put more trust in companies that have been around for a long time.