Is there any extension that helps me to navigate to product page from backend with only 1 click? And how much is it? thanks!
There is the application called Store Manager for Magento and it is desktop program to work with your Magento catalog (faster add/manage/modify products, attributes, customers, orders, perform bulk changes etc). It has the option to view product page (front-end) directly from the product (right-click on products -> view Product Page) -
You can download 14-day fully-functional version of the application and test how it works - check the link in my signature.