The first 100% of the cost is 20% writing, testing and certifying it, and 80% maintaining the result.
The additional 100% is the cost of rewriting it because you didn't actually write it to be maintainable.
The first 100% of the cost is 20% writing, testing and certifying it, and 80% maintaining the result.
The additional 100% is the cost of rewriting it because you didn't actually write it to be maintainable.