[HR] Looking for a d20 degree of success mechanic

A question re-posted in brief from my blog.

What if a Magic Research throw could indicate a degree of success that might reduce the time and gold required to accomplish a task such as replacing a spell in an arcane repertoire?

I suspect some easily adapted d20 degree of success mechanics are out there. What do you recommend?

http://www.bythisaxe.co/2013/05/1-week-and-1000-gold-pieces.html

How about the magical experimentation breakthrough rules in Players’ companion?

I think that’s already the framework you’re looking for. It helps add system verisimilitude, as well.

Exceed by 5+, 10+, or 20+. Also gives you minimum levels of 5th, 9th, and 11th.

Maybe just make it 10%, 20%, and 30% less time and gold? or 5/10/15% - which is what I’d likely do.