> Investors often wait months before investing in order to let a little more information surface, during which time the valuation can (and often does) increase by literally millions. Given that the cost of doing the extra research for each deal would be nominal...

Not sure about math here. Lets say that average increase is $0.5M and only 1% gets funded. In that case it is around $5,000 per study to break even. I do not think investors could fit reliable evaluation into this money.