Your absolutely right, the amount I pay doesn't affect the companies ability to generate a return. Which is exactly why the price I pay is important in determining the return I will actually realise on my investment. If I pay too much, the return I actually realise is going to be much lower.
A company that generates $2 of earnings per $1 of price paid by me is more valuable to me than a company that generates $1 of earnings per $1 of price. If they were the only two options, you'd pick the former every time.
ALU Price at posting:
$12.78 Sentiment: Buy Disclosure: Held