So I contacted John Butler (the business proprietor) at Buybrakes.com as I really wanted Red calipers if I was paying for a BBK. They contacted Stoptech (apparently they are a very large distributor for Stoptech) and I guess they had a "partial" kit and agreed to manufacture another red caliper and provide it for the overstock sale price of $1800. This is like half price!
I was able to get an awesome deal and John was great to speak with (another enthusiast). He said they still have one black BBK and one silver BBK for BMW F10 remaining at this sale price if anyone is interested.
Try contacting him through their website buybrakes.com. I just sent a text inquiry to 702-903-1713 to get started. I am not affiliated with them in any way, just thought I would share what seems to be a great deal... (He said the M3 BBK sets all sold out the first day of the sale). I already received the order confirmation email and he said it should be about 3 weeks to complete the kit and ship it.
https://www.buybrakes.com/stoptech-brake-kits-sale-on-overstock-big-brake-kits