Just if anyone of you happened to get domain from Regiter.com, a domain with .com extension is priced $35/yr and same domain with .com extension is priced $10 at GoDaddy.

What exactly is the reason behind this difference? Why would anyone get domains from register.com if they can find cheaper pricing at GoDaddy or similar reputed registrars/resellers?

Is Register.com serving special domains?

Well, Register.com has MANY reason, the same as OTHER high end companies. Sometimes they will have BETTER service. You might pay godaddy $10, but their support tech's might take over 24 hrs to help you. While "usually" expensive places will have better support, who answer within mins or an hr.

It's all in market positioning and in profits IMO. It may be that Godaddy has to sell 10 domains to make the same profit as register.com makes by selling only one. So long as register.com can sell at least 1/10th the domains Godaddy does, they're doing good.

(Fictional scenario of course)

Because not everyone is interested in the cheapest price. The service level is important as well, especially for something as critical as a domain name.

You only have to read up on the RegisterFly fiasco's recently to realise "cheap" is a relative term, and losing your domain could be very very expensive to your business.