As much as I can. Ideally, I'd like to be around 200k on release, and I'm at ~100k right now. Already have all of my professions maxed out so it's pretty much just make money where I can until MoP is out.
Have mats and stuff stocked for 350k-ish at the moment. And as much liquid gold. Don't know if I'll bother stockpiling more or not. Time will tell.
I will spend little to none being I have the characters to go out and farm all mats I will ever need. Its all about time is money.