What does nick mean when he reflects that Gatsby "paid a high price for living too long with a single dream" (Fitzgerald 161)?

Gatsby's one dream was attaining Daisy. Everything he'd done or accomplished during his adult life focused on the dream of one day being the man who could offer her everything, a dream that would end with the two of them living happily ever after. In the end, Gatsby paid for that dream with his life, a huge price for a dream that could never be realized, a dream that could never come true.