i wasn;t sure where this would go, so I put it in here since it dealt with BC. I found a nice way to get BC(Blackwell Credits) without having to sell anything, and it's not that hard to do.
Firstly, I built my E.D.E.N Farms high enough to build a Biosphere and upgrade it to level 1. Then after I built the Biosphere, I upgraded enough to use my stargate to help with food income. Do not upgrade your Biosphere past level one for now, instead, just keep upgrading your E.D.E.N Farms to increase your food income. Since your Biosphere is only level 1, it's max storage is 2,400 units of food. Once it hits that limit, for every 4 units of food you produce after that is converted into 1 Blackwell Credit. By doing this, you can still gain all your other resources, without the loss of income to your other resources that you get from raising your taxes to gain Blackwell Credits. Now the reason you upgrade enough to build your stagate is, once you can produce Marines(Infantry Unit) you can send them to raid any nearby mines for resources. Usually you will get food because everyone raids the mines. You can use the food from the mines to help reach your max food storage if you use any food to build.