I understood your question in that way that you ask whether you can make profit by selling buildings?
If so... I have to come back to this manager issue

It is difficult to say how building trade will develop in course of the time, as everybody is becoming richer here...
And if you want to sell it to the system: Click onto the building you want to sell, you will see "sell building" and there you can sell it back to the system. But pls keep in mind the advice given by the others here
