A. It really depends on whether you would need it or not. Stock enables you to calculate your storage costs, list all stock items with details of each item and is fully integrated with sales and purchase ledgers.
The stock builder provides an extra layer of functionality. It enables construction of a new stock part from other stock parts. For example, if you sell two items indivudally, but also want the option to sell both items as a bundle, the stock builder will create that for you. Here’s how