A lot of the time, there is a particular individual who has the cheque-signing power up to $X. For such a person there is a psychological distance from the act of spending -- it's not a personal loss if the purchase doesn't pan out. Whereas for individuals spending their own money, the simulation heuristic makes purchases of unexperienced goods or services much scarier.

Hence my "monopoly money" remark.

I think you have correctly reflected that a purchasing decision may have input from many different parties. But these people matter from a sales perspective only so far as they influence the decision of the person with the chequebook.

The flip side of that is there's usually little for that particular individual to personally gain from spending that monopoly money, even if it actually helps department X cut costs or raise sales dramatically, whilst a conspicuously bad change to companies' spending patterns may still get them fired.

I believe one of you is writing about the psychology of the buyer, and the other it writing about the sociology of market penetration, or the sociology of corporate decisioning.