Custom Pricing Configuration Using Extensibility

Most of the time, when you want to present customizable products to your customers, you would do the following at a high-level:

1. Create one or more products that each are using the "User Supplied Price" option for pricing
2. Create a custom view or custom module that calculates the price.  
3. Submit the new custom product to the cart with the price that the custom product should be charged

Examples of this can be seen in United Sport Apparel and Custom Glass NY.  

In your case, you also want to manage the base price in Hotcakes, which is not how they're doing it.  The base prices exist outside of Hotcakes.  However, you can still do this.

First, create a new Product Type Property called "Base Price."

Now, create a new Product Type for customizable products.  Make sure you add the new Base Price product type property to it.

When your product managers are editing a product, the base price is a new field that they can manage in the product edit view.

This will be displayed like shown below in the default viewset.  Be sure you create a custom viewset, or modify your existing custom viewset, as necessary.  This may include creating a new view specifically for this product type.

Now, your product customization process can pull the Base Price from the product details using the API.