A department store is a convenient place to look for tools because other shopping needs may be met without ever leaving the store. A customer service representative specially trained to help with tools and hardware will know which of the store's products best match the customer's needs. Sears is a department store that sells many different sets of taps and dies.
A discount store is another way to one-stop shop and spend a small amount of time accomplishing multiple shopping tasks. The customer service representatives at a discount store may not be as specifically trained as those at a department store, but they can find an item if the customer knows for what item they should be looking. Wal-Mmart and Kmart have several tap and die sets available.
Sometimes when looking for a specific item, it helps to go to a store specifically suited to the task. Hardware stores and home improvement stores will usually have everything necessary to complete a project at home. The customer service representatives at these stores typically have a wide knowledge of projects and tools and are capable of assisting customers to find the correct tools quickly and efficiently. They may even make suggestions as to how the project can be accomplished. Ace Hardware, The Home Depot, and Lowe's all carry taps and dies in most sizes.
When a customer knows exactly what they need to finish a project, sometimes the most time-efficient way to purchase tools is to do so online. Consider brand, size, and other customers' reviews in order to get the expertise desired before purchasing an item. Amazon.com carries many sets of taps and dies.