Media for LED DMX512 controller?

LED DMX512 controller?

I'm looking for some guidance on what I should get for a LED lighting project for the garden and home, it needs to be changeable and re-programmable to keep up interest so for instance at Xmas be able to do the lights (altho I'll fight that impulse my partner has :D)

After doing a bit of reading and talking to some folks I've been told I might consider buying a DMX512 controller - one that is programmable via software: -

Daslight DVC GOLD USB/Standalone DMX Controller Saturn Titainus Control from Chamaeleon tec

Rather expensive items!

And I was wondering if you folks knew of a cheaper alternative that would still allow the functionality of being able to set moods in an architectural sense to create a light show via an application on a pc (win or Linux), rather than hand coding to get the stuff working.

The other bits needed ill leave for my other half to have the joy of discovering but a good flexible controller that has scope to create lots of different things would be of help, he plays with X10 (feels sorry for the house and myself) and is a C/C++ programmer.

Thanks! Mel :)