Pre-orders are charged when they are sent their serial numbers for the product. I was charged the day the first Beta was released. So Star Dock has my money already for GC2.
I recall Brad saying that his company funds new work on the existing revenue streams. Any advanced money, such as pre-orders, is just a bonus to the company, and is not something that he ever plans on, as it is too unpredictable to include in any project budgetary planning.