The cost of adding a feature isn't just the time it takes to code it. The cost also includes the addition of an obstacle to future expansion. The trick is to pick the features that don't fight each other.
“The reason is that a military defeat of Britain will bring about the disintegration of the British Empire. This would not be of any benefit to Germany.”
“All I could do at school was paint and draw and that was the only time I ever passed any exam. It was the only thing I ever got right at school.”