I've been doing this for a long time, and have amassed such a loyal following that my customers have, in the past two months stepped up and loaned my company $300,000 to build a bigger factory.
Here are some words of wisdom to live by when you are trying to "keep your costs down".
1. Garbage in. Garbage out. You can't take crappy ingredients and make great things from them. Cocoa powder is the bottom of the barrel in the chocolate industry.
3. If you use liquor, you don't need to add fat. The liquor is +/-50% fat already. Use a homogenized milk, or even a 2% fat milk. That works best.
4. Under $20, if the quality is there, nobody cares about price. This has been proven time and again with movie theatre admission, theatre popcorn, wine, chocolate bars, and way overpriced cappuccino's. Make a product that WOW's people, THEN figure out your costs and charge accordingly. People will pay the price you ask.
5. With respect to a "vegan option", I did almost 6 months of research on this one, and it's a total bust. I made a drinking chocolate with Soy Milk. Anti-soy vegans complained. I made a version with Almond Milk. Nut allergic vegans complained, plus it tasted nutty. I made a version with rice milk, and an amazing whipped edible oil product for the top (or optional toasted marshmallow). It seemed to pass all the "acceptability tests" from all the hypocondriac fair trade organic non gmo wingnut vegans out there, so advertised the heck out of it. In fact I got FABULOUS feedback during product trials. So.... I spent several thousand dollars on marketing, literature, signage, social media (vegan facebook pages, etc.), and sold.... you ready? 40 servings. I also threw out a lot of pre-prepared drink bases, because nobody purchased. If you would like to create a version that caters to the 6 vegans out there in the world at the cost of quality to those who actually pay your bills, well.... I think you are selling yourself short.
Well, I hope that helps.