They need money to buy the components to build the machine.

They take pre-orders for one batch of machines. They build that batch of machines. They soak-test those machines, and then start sending them out.

Now, with the money from the pre-orders and from the soak-test bitcoins, they can build a second batch which they keep.

There is only a certain amount of BTC to be had every hour. If they brought these in by the bucketload they could dominate the mining utterly. They would then also effectively control the network people may lose trust, BTC value could tank etc etc.

>If the amount of profit from using these machines was greater than the profit from selling the machines.. then the company selling the machines wouldn't sell them to you

Unless they couldn't make the machine without you paying for it first. Or they don't want to break the system by reaching >51% of the network (after which the value of btc plummets down immediately, thus making the machines worthless).

Why would the value of BTC plummet if you reach 51% of the network?

If a single group controls more than 51% of the mining power they can cheat the system (double spending, things like that). If such a monopoly was created people might lose their trust on Bitcoin and try to leave the system.

There are companies that manufacture and sell everything else that people use to make or earn money, so I don't see why this would be any different.

A lot of people will tell you, "Think of the upfront costs" and that sort of thing. My opinion however is that it's nothing we haven't seen before. Maybe the customer makes money in the long run. Maybe it takes 6 months for the unit to pay for itself. The manufacturer on the other hand gets their profit up front. They don't have to wait 6 months, and they don't have to worry about whether the value of bitcoins will crash.

Certain profit today, vs. less certain profit of greater magnitude tomorrow. Seems familiar.

Or, they could make money.... ignoring the price of electricity for generating said money.