Line item should change the price I have this problem in Drupal Commerce: a line item should change the price of my product, that is based on customizing the users (ex. product base $10 with customization $12, customization is line items). 

This is possible working on Rules, but you only see final price after you add the product on cart, I should instead see the price change in ajax so the users see final process before add to cart. 

I've not found solutions online. The basic scenario is like this: 


You buy a shirt based  =$10 
The user customizes the shirt with your name and = $12 
The user customizes name and logo = $14


I am working with Kickstart 2.0
The functionality you're looking for doesn't exist at the moment. I'd describe it as wanting line item field value changes to trigger a refresh of the Add to Cart form and the injected product fields. You can follow this feature request, though I'm not sure it's likely to be addressed soon:

https://www.drupal.org/node/1541886