A great place to go is 99 designs. It might be a little over the top for a personal website, but if you take a look at the currently open contests, you can get a pretty good idea of what you will get for your money. You have a lot of input on the final design. People submit drafts early and you can rate them and comment on them.
You can see what this contest got for about $200 dollars. If you are looking for something more simple, I bet you could get away with even less!
Also, have you thought about using something like Wordpress or Drupal for your personal website? Specifically with Wordpress, you don't even have to have a blog section, you can just use the templates as your site design. There are some pretty fantastic, free Wordpress templates out there that you could use. If you want to make things a little bit more interesting, you could integrate some free stock photos from this website. I have gone this route and it makes managing the website extremely easy.