What is on this page is finished buildings, not company profiles. Every one says who built it. Where the cost is public it says the figure and who published it; where it is not, it says so and why. See one you like, ask for one like it.
Rows tagged as sample data are there so the page has something to show. They are not real projects.
A builder published price is a contract price the builder chose to make public and the platform does not guarantee it. A declared cost is the estimate an applicant lodged with government and is not a contract price.