Who said
Legend of Conan would only cost $20 mil.?
It's not about whether they can afford it, it's about whether they think it's worth investing in, and its profit potential (and more often, it's about how much money the deals in and of themselves can generate prior to any production).
Regardless...
Scenario. I used to be a millionaire, but I went away and became a chef for ten years. Now I'm returning to the business that got me started, but my mojo seems to be gone.
You give me $500,000, I promise that you will make 50% profit on what you invest in me. The first four projects I invest $400,000 in fail to produce a profit, and even lose some money. The fifth breaks even.
I knock on your door. Would you invest another $500,000 in me?