If you don't understand this, I will gladly buy your early-date pre-order for what you paid for it: $1300.
The price of BTC will fluctuate so if you buy a rig that mines 4.5BTC/day and the price of BTC falls to $30... Can you see how the price of BTC makes paying $10,000 USD today for a machine you MIGHT get 3-6 months from now a real losing idea.
If you don't understand this, I will gladly sell you MY early-date pre-order for what I DIDN'T pay for it: $500. ... and I will give you the same assurances all the eBayers give you like a nifty .jpg of some invoice for $1,300.
I'm glad this thread is still going. I'm sure you'll notice that today BFL announced a price doubling of all their units. Discuss.