Shall I use both .com and a localised domain or Shall I use .com only?

I have a classified website and Now its running on the internet fine. It has a .com domain. In there users can put advertisments to any location by selecting the country and city.

So I also buied a local domain ( My country domain ) to deploy a site in my country.

The reason why I think it good to go for a localised domain is I beleive that any country's peoples' trust their localised domain.

But when I do that I am not going to use any localised language or any thing.

I am just upload my project from this new domain.

Also my some friends says If my country can select from .com version why you should go to localised domain?

That also make sense.

Also I am worry about SEO thing. What will happen if my country domain get a bigger traffic and then will it appear on top of the results in google? Will my .com domain come 2nd?

So What are your ideas?

What should I do? Shall I stick with .com only or Shall I use my localised domain?

I need a descriptive answer please.