Levein insists it demonstrates the ambition of United chairman Eddie Thompson and his son Stephen, the club chief executive.
He told The Courier: "Once again I've really got to thank the chairman and Stephen Thompson.
"When I found out that Roy would be available they did all they could to make it possible.
"We had a bit of money left after Noel Hunt going but this transfer went a wee bit past my budget - but again they have pushed the boat out. "After selling Hunty and Barry Robson, as well as getting to the CIS Cup final, the club made a good amount of money last year. "Instead of just putting it in the bank the chairman wanted to pay off some of the debt and invest some in the team. "He's really done that this summer. I've had fantastic backing from him."