If you want to achieve 100% perfection on any project, product, service, or process, it will take about 70% of the cost (time, money, etc) to reach 90%. The return of the final 10% is not worth the cost (final 30%). There is a large diminishing return.
Therefore, unless you are a brain surgeon or rocket scientist, don't strive for perfection. Instead, you want to achieve success and provide value.