There are lots of different types of projects. Sometimes you're asking people to invent things for you, and you're the only conceivable customer for that thing, and (like here) it would be weird and perverse not to require all the data/specs/whatever for that thing. Other times you're buying something that's already been invented, with many existing customers, and the data/specs/whatever for that product line are worth much more than the units you actually want to buy, and it wouldn't make any sense to have to buy out that entire product line just to use the product. It might be hard to make simple rules that distinguish between these cases, and all the gray areas in between.