Piping audio from arbitrary program to Airport Express
Honestly I'm not aware of any (free) options that I can vouch for.  I've used a couple of solutions with little success.  What I can offer, however, is some praise for the AirFoil solution which has served me well over the past couple of years.  

In terms of VLC, I would also add that there is an issue with syncing the audio to the video when using AirPort and VLC (or any other video player).  The Rogue Amoeba folks get around this by supplying their own video player, the Airfoil Video Player, which is capable of handling most video inputs and also making sure to keep the video display in sync with the audio.

So, while this doesn't answer your question as to other options, hopefully what I can do is allay your fears about wasting $25 on a product that may or may not work.  In my experience it works exactly as advertised.  And I've had good luck getting responses from the developers when I've had questions or minor issues.  

Highly recommended software.

Good luck in your search.

-Steve