[v-erne]

50% off is understandable ? Where can I find such forgiving clients? My clients lawyers would eat me alive if I would start to bill them in such manner. They dont want to hear about uncertainty - they are buying professionals and this kind of estimations looks to them like we dont know what we are doing.

[AlexCoventry]

Maybe if you're building the nth monitoring dashboard or something. The work I find interesting is inherently uncertain, though.

[v-erne]

Sure we all know this, but for business people with money this looks fishy. This xkcd sums up the problem perfectly: https://xkcd.com/1425/

How non technical person can tell the difference between task inherent uncertainty and Your incopetence? They cant that's why they will buy Your competition that will claim there is no uncertainty.