Head gaskets run any where from like $40 to $140, and I wouldn't suggest to do it your self if it's something you've never done, especially as it's tough to un-screw up what you've screwed up when it comes to valve train and head work, for example if you don't pull the cams, and replace them at TDC, you can say good bye to your motor when you go to start it up.

Though, yeah, it would be a great time to put in some parts.

Later,
Aj