If you go to their website, they just changed the way you have to purchase to get to the Stage 2. I just bought mine as a full Stage 2, but after that they changed to having to buy Stage 1 and then upgrade that to Stage 2. No more Stage 2 purchse alone.
Cut and paste from Burgertuning.com: "Stage2 support for the F10 is very limited and not available for all vehicles. Stage2 for the F10 is ONLY available by purchasing both a Stage1 system and a Stage2 add on upgrade kit from the upgrades order page."