Lucas thought ESB should have been made worse for less money. He got his way the next time around.
I highly doubt he thought that. I see you are completely detached from reality like the guy in the other thread (http://originaltrilogy.com/post/id/1050968). Budget/time constraints are there for a reason - not to bankrupt. He most likely wanted to make as good film as possible within the given budget/time constraints. For that you need a director who can make great shots in minimum amount of time.
And your statement is especially stupid, considering Lucas put everything he had into the film. The evidence of that is that he had to go to Fox for extra 10 Million after it went over schedule/budget.
Making of Return of the Jedi is a great read and lays out how Lucas went about cutting corners on the film. At one point during the filming of the Sarlacc fight the crew brought him an animatronic tentacle to use, but he had specified that a simple rubber tentacle would suffice, and so he refused to use the clearly superior prop to make a point. It seems petty and counterproductive now, and some of the effects could have used more than matte paintings, but it did keep costs down.