It may look old, to you, but it doesn't mean that it will also look old for your visitors.
I too have an affiliate website, that looks old, for me, but when I let some friends take a look at it, they think it's way much better compared to other websites due to it's simplicity. Good looking websites sometimes are too complicated to navigate and maintain. What's important is you'll be able to show what your viewers are expected to find in your website/page. Most users (that i know of) prefer what they find on your website (content) than it's design (GUI).
Good design is good but the content is more important.