Hello, yes you can pay other players with in-game currency to build something for you.
As for the protecting yourself in case of a scam, I would just be sure to take screenshots of the agreement in the in-game chat, (or wherever the discussion may take place, such as discord) along with a screenshot of the amount of money you send to them. And then in case they do not withhold their promise, when you report to staff you have the evidence you need to do so. But there is no sort of contract that has been created by staff nor the server, so go about the situation in whichever way you feel most comfortable.