It sounds like you're asking about buying fresh new houses, so I'll give a bit of details about those.

The long and short of it is that your money goes to the one of two things: If it's part of some whole new neighborhood that just opened, some promoter paid a whole bunch of construction companies to build 300 houses and a bunch of other buildings up front, and you're paying them. If it's just a house torn down and rebuilt, you're paying a single construction company that paid for the old house and lot, then paid to demolish and rebuild it, all in advance. Then they make profit once the house is sold.

Howe much everyone involved costs has no real answer because every project and business has their own guidelines.

Generally speaking, the ones paying a couple dozen million for a whole new development up front will expect to make more profit than the workers who did the job. This is compunded by them doing a whole neighborhood, so they have little to no competition, they know everything will sell, and they'll be the ones selling.

The moment there's more promoters, everyone's profit margin will get smaller, but not that much because they'll often collude and get away with it. workers won't get paid a dime more.

In truth, the small nd medium construction companies often go bankrupt because of how many unforeseen problems can baloon up costs after they got locked in to a fixed sale price, or because of their obligation to repair building flaws. So, since they take all the risk, and the workers merely show up, do their job, get a guaranteed paycheck, and find a new job if the company sinks, they don't get as big a piece of the pie as the promoter or construction company.