I went to mocafe's web site and saw a Wild Tribe Moka. Is this what you are using? While I've never try it, it looks like some sort of chocolate and coffee powder. Have you try to replicate the taste using chocolate syrup, espresso shots and milk/yogurt/ice cream? To start out, you might want to consider making your own chocolate sauce. Buy any high quality semi-sweet, or dark chocolate such as Gheradelli or Guittard and melt it with hot milk to a thick syrup consistency. I go through enough that I buy the 10 pound block, but you can start out buying them at Costco type places at about $2.20 a pound. For a super rich chocolate drink, you need no more than 6 oz (my guess is less) per 24 oz drink which will cost you $0.83. Added two shots of espresso at about $0.20, 6 oz milk at about $0.18, cup, lid...another $0.20, you are at $1.41.
Also, at 24 oz, over $4.00 is not unreasonable. I'm in Connecticut, my 20 oz blender drinks are over $4.00, they are similiar to Starbucks' prices.