This makes me sound like an asshole, but it's really not Fractal's problem if you need to sell your current gear to afford the FX8. If you get the invitation and can buy it, cool. If you can't, then you need more money at that point. This is a top-of-the-line product and you simply need to pay for it when your name is called.
I understand it, but it's like people get on the wait list and want a month, then 2 week, then 1 week notice for their invite to come in so they know exactly when to sell their gear. It's a wait list. When your name pops up you need to be ready. Units have been shipping out and not everyone who gets one reports it on the forum. So a lot of this guess work seems pointless since there are huge holes in the data.
If you stop checking the forum every few hours, go about your normal life and play the gear you currently have, I bet your invite will be sent out much faster than if you dwell on how you don't have it yet.