Minor correction needed here. Judas gave the money back to the High Priest.
They, rather then return tainted or blood money back into the treasury, used it to buy the "field of blood" for the burial of the poor. Yes, it was the same place where Judas hanged himself.
Whether it was purchased because of that or he chose that place because of where the money came from is unclear. I have heard it argued both ways.
a. cricket