First let me say I think Biotest products (Superfood, Flameout and Metabolic Drive) are great.
But stating that if you can not use Metabolic Drive you should not do this diet is just not fair IMO.
Stating that if someone sells a micellar casein product that is cheaper than yours is probably of less quality is also misleading.
My protein is 80% Micellar Casein and 20% Whey Isolate, I get it from a long standing and reputable company. I am guessing this is a higher % of Micellar Casein than Metabolic Drive yet I am paying less.
Some of the reasons are simple, they can ship in a plain plastic bag that is free. So I can get 5 pounds and I do not have to pay for the cost of the containers. Buying in bulk is always cheaper, I am sure if Biotest sold 10 pound BAGs of Metabolic Drive they could make it cheaper, maybe not by much but it still would be of less cost to produce and the savings could be passed on to the consumer.
IMHO you are doing a deservice to your diet by making such a statement. Your diet works if the right supplements are used, which you can get from various companies of excellent reputation (like Biotest).