Call For Price is a plugin in which you can display "Call for Price" text inplace of price for the products that have 0(zero) price.
You can change the "Call for Price" text to any text you want.

It has a option to choose whether "Add to Cart" button for that product will be enabled or disabled, in both the cases user wont be able to add device to cart but if the button is enable then after clicking the "Add to Cart" button user will be navigated to the product description page.

You can change the "Add to Cart" button text to any text you want and it will be reflected in the page only when "Add to cart" enable condition is selected. Default text is "More Info!".

For disabled condition, button will be disbled with "Add to cart" as text and customers won't be able to click the button and won't be able to add that product into the cart.

It works for all the different type of currencies and for both Grid and List view.

To enable any product for Call for price condition, you just have to change the price of that product to 0(zero). Once you change price as 0 for a product, then you can see Call for Price text instead of product's price and Add to cart button will also change according to your settings.