Ebay is always an option. lots of people are selling off their excess DV models. But honestly you should start small. if you seriously want to get into chaos pick up the Dark Vengeance starter box. Since everything is marines you can easily convert the Dark angels to Chaos (or run them as fallen angels). that right there should start you off at around 1K worth of troops and some fast attack. From there just pick up a box or two when you have managed to get everything previous painted up vehicles and heavy support with maybe a flyer at some point. And don't let your back log build. both @Tawa and myself are prime examples of this and we struggle to get through the hordes of models we have. but your initial investment should only be the codex and the starter box if you are serious. your old guardsmen can also be turned to the service of the dark gods as traitor guards or cultists if you prefer.So I was just browsing the GW webshop and wow, I know this has always been an expensive hobby , but jeez, 80 odd bucks for a codex? Things have gotten a touch more pricey I think. Anyway, any advice on turning to Chaos on a relatively average budget?