So power tools at HD and Lowes don't have cheaper parts put into them to make them cheaper? Like different bearings, triggers, and other parts in a power tool?
This is where the conversation gets a little tricky. Places like the Home Depot spend all day, everyday looking for ways to keep costs down, and they are very good at it. For the most part, their whole mission is to provide QUALITY at LOW COSTS, and they are pretty serious about this, and because of their volume and buying power, are not shy about hammering their suppliers. they make their vendors manage the inventory, and want guarenteed lowest costs, rebates, free frieght, mark-down dollars, no questions asked returns, marketing funds, first-fourth born children, etc....
Manufacturers sometimes find themselves in a bind, and have to balance trying to find a way to be profitable, while meeting all these expensive demands, and maintaining a price point that will keep consumers buying. Many times, a manufacturer will accomplish this by creating a new model, which is often done by simply "dumbing down" an existing item.
So for an example, lets say that Joe's WhizBang Power Tool company makes a top-of-the-line miter saw that retails for an established price of about $700 in contractor supply houses. Let's say Home Depot wants to stock this item, and insists on being able to retail it for $549. Maybe there is enough margin in it, that without making any changes this is doable, maybe not.
Now the sales department at Joe's has to have some meetings, and make some choices based on their situation. Maybe this miter saw is VERY profitable for Joe's, and they can easily sell it to HD at a price where they can mark it up, and resell it for $549. In this situation Joe's has two choices, they can sell it as-is to HD under the same model number, or they can simply create a new model number
WITHOUT changing a single other thing, this way the supply houses don't start grumbling, since the $700 saw
MUST BE DIFFERENT from the $550 big box version, since the price and the model number are different
Now if Joe's CAN"T make money selling the same saw, they will often take the old saw, swap out the motor, or some components, with lower cost versions, create a new model number and offer that to HD.
The obvious question that remains is COULD the manufacturer swap out a lower priced component without changing the model number and the answer to that is yes. Most power tool companies will buy components from a couple different sources, or at least have a secondary source for most parts, so if one trigger factory has a problem, it doesn't keep them from producing tools. this is why they often require you to provide serial numbers when you order parts, so they know which motor was used in your saw, or which trigger, etc, but they also use serial numbers for warranty info, and overall longevitity tracking, so just because someone asks for your serial number, it doesn't automatically mean there is any hanky-panky going on. You'll also see model numbers like a 5521A, 5521B, 5521.1, 5521.2 for similiar reasons
You could walk into your local contractor supply house (or home depot) today, and buy two identical power tools at the same store, and it's possible that they could have 1 or more differnet componets used in building them.