You're all looking at this wrong.
If we reach 8000 MOQ at $1.00 per, BlindAssassin111 is given $8000 of our money to order with. On the other hand, if we reach 10000 MOQ at $0.80 per, he is still given $8000 of our money to order with. Nothing wrong with that, he makes no extra profit or less profit from selling 10000 over 8000.
However, this is the scenario you are thinking of:
Reach 8000 MOQ, raised $8000.
Instead of waiting to reach 10000 MOQ, go ahead and use the $8000 to order 10000.
Sell these 10000 at $0.80 each instead of $1.00 each.
By this point, we have affirmed that 8000*1.00 = 8000 and 10000*0.80 = 8000.
However, let's say this GB has only generated enough interest for 8000 housings and lets say he goes ahead and orders 10000 housings.
He will now sell 8000, as this is the only amount of interest generated, but at the 10000 price.
8000*0.80 = 6400. And now he has 2000 housings left which total up 1600 if sold at 0.80.
Remember that we only generated enough interest for 8000, though. This means he is left with 2000 that will not sell. At least, not right away.
BlindAssassin111 is a person, not a vendor. He is not able to afford to let go of $1600 in the hopes that he will eventually make it back over time of selling the remaining 2000.
I hope this clears some of this up.