title: ofbiz product relationship
body: <p>I purchase from a manufacturer gift cards (not virtual ones, but real plastic ones), and keep it in my warehouse as serialized inventory,  this base product is  not salable.</p>
  
  <p>i sell them as another products, that has additional virtual charachteristic (fixed one, that cant be configured by the customer). e.g. i can have 3 diferent products of: 100$, 200$ and 300$, and have the style of the base product in the warehouse. again,all defined as separate product in the catalogue.</p>
  
  <p>I thought of modeling the inventory product as "configurable product" and the dependant product as "configurable product instance", and add the fixed configuration as features of the product. Is this the correct way? i see configurable product example, only when customer is defining configuration (the PC001 sample). 
  any other way? (maybe variant? though, my understanding it fits only when base product is virtual)
  Thanks,
  Amit</p>