Quote Originally Posted by jon_h View Post
Have a look on google about using coffee or tea as a stain.
That's about as cheap as you can go.

Failing that a small pot of wood stain.

Is it bare wood? If it's bare a coat of oil should darken it a bit, if you get the wood wet with either water or white spirit that should give you some idea of what it will look like.
Beware of water based stains as they dont "rub-out" like spirit stains