The Fountain (2006) was initially supposed to star Brad Pitt and Cate Blanchett with a $70M budget. But Pitt ditched for Troy and the project was scrapped. Aronofsky rewrote the script (cutting huge set pieces) and got Hugh Jackman and Rachel Weisz on board. What was really cool was his use of low-cost macro photography for the space scenes instead of CGI.