Custom Pricing based on anonymous customer input Hi gurus and fellows, 

I am a newbie at DrupalCommerce, though I have been designing website for a while using Drupal. 

For our new project, we need to provide some custom pricing rules, based on user input. Anomymous user fills in a form, and, based on his input, we compute some special 'discount' (sort of).  Let me emphasize that user is not connected (registered), and its data is kept in session only. 

As far as I know, we need to set up some "Pricing Rules", but to tackle my problem, I can only see "User has role" / "User is blocked" in the possible conditions, which address only logged-on users. 

How you would you do that ? 
Do I need to write up a custom rule ? 

Any hints much appreciated. 

Thank you.
User has role can indeed be used to setup a rule for Anomymous user, see the image: