The timeline from preclinical work to a new drug application has a ~5% success rate. A major bottleneck in this is target selection, which research should in principle help with. Giving a number for how much science improves this is iffy, because a lot of research is in fact pointless, with tiny specks of gold. Overall, when comparing money spent vs. its effects (ROI, economic spillover, cost-savings, etc), its definitely worth it.
