I want to display different prices for the product according to visitor's country.
For product ABC:
Price x should be displayed for country A.
Price y should be displayed for country B.
Is there any way to do it without creating any other store? Thanks in advance.
As standard, price can be set on a per website basis. In System > Configuration > CATALOG > Catalog > Price > Catalog Price Scope > Website
So, if you then set up a new website within your Magento for each country you will be able to use the configuration scope to select and set the price for each countries website.
More on creating websites can be found here: http://docs.magento.com/m1/ce/user_guide/store-operations/store-hierarchy.html
More on the configuration scopes can be found here: http://docs.magento.com/m1/ce/user_guide/configuration/scope.html
Does this help?