Multistep information collection with reference to price addition or substraction As I have posted previously, I was trying to built product kit with customization option. But there is no easy solution for that and diving into the coding using drupal commerce or ubercart need understanding of those module first.

So I reviewed the requirement again and saw, checkout is not required. I just have to declare the product kit &amp; gather the information...

Have a look here on this link - Customize Your Laptop

I have to declare package like this. Where there would be default price for kit which will be sum of all default product. Every kind of product, there would some other option either in radio or checkbox and at time of going through step by step user can give their input and total price would change accordingly.

I will tell you the options which I have till now -


Webform (But the reference price change would be an issue)
Quiz (Same problem)
Form API (Client can't create package from them-self that is the main criteria behind this application)


Can I have some suggestion from someone, like what can be my roadmap or which module can help me with it by some tweaking or their API?
If you dont want the shopping aspect of the site then I would do the following.  


Create the content types called the product. 
Add a field with a drop down with the different steps (Processor, RAM etc)
Add a field to add the price. 


Create a custom module with formAPI to call these values and do the needful.

Multistep forms would be the way to go. With Ajax to give it some flare. 

You can download the example module to see how the form APIs work. The examples you would want to check would be the form example and ajax example