As jz78817 said, copper, iron, and maybe other metals. The materials alone are expensive. Take a look in the electrical aisle at Lowes or Home Depot and see how much basic copper wire for your house costs. It ain’t cheap.
Also, whenever you make anything, there are a lot of up-front costs involved, like paying the designer(s) and devloper(s) of the product, setting up and tooling the factory, etc. Depending on the product, these costs can range from tens of thousands to many millions of dollars. I don’t know about motors, but just for giggles let’s say it costs around $500,000 or so to set up the factory. After that, it’s all labor and materials. Let’s say you spread out your up-front costs over 5 years. In that 5 years, if you make a million motors, your up-front costs work out to 50 cents a motor. But if you only make ten thousand motors, your up-front costs work out to $50 a motor. If you then have $50 of labor and materials into each motor, that’s $100 in costs just to have your motors pop off of the assembly line. Now you have to tack on overhead costs like warehousing and shipping, and maybe you’re up to $150 per motor. You need to make a profit, so you sell the motor for $200 to the retailer. He needs to make a profit too, so he sells it for $250 to the end customer.
The customer is thinking there’s only $50 worth of materials that goes into it. Why is it so expensive? I must be getting gouged! But in reality, neither the manufacturer nor the retailer is making a huge profit on the deal. They are making enough to make it worth staying in business, but not much more than that.
It costs maybe $50k to $100k to set up a line to make little plastic things. After that, the costs are a few cents at most per thing. Plastic things in low volume are expensive. Plastic things in high volume (millions of thingies) are dirt cheap.
The factory for computer chips is ungodly expensive to set up, but after that, each chip costs a few bucks at most to make. This is why there are only a couple of major CPU manufacturers. The costs up front are so huge that you have to sell millions of chips to make your money back, otherwise it’s not profitable.
Motors sold by the millions, like those in hand held power tools, are pretty cheap. Larger motors like those used in a table saw aren’t sold by the millions, and have higher material costs going into them, which is why they aren’t so cheap.
Because there aren’t many of them made. Again, it’s the setup costs plus the manufacturing costs plus the cost of warehousing and retailing the item. Plus there is some supply and demand going into it. The manufacturer doesn’t really want to sell little bit parts like this because they mostly sit in a warehouse somewhere and are then sold in very low volume, so they jack the price up. The customer is willing to pay the higher price (because otherwise they won’t have a working tool) so that’s the price that the switch settles on.