In every enterprise I've ever worked at, the purchasing process is a nightmare - it invariably takes months at best to purchase anything, and the bureaucracy, meetings and wasted time will cost you your soul. When you add up all the wasted man-hours it takes to purchase a $100 app, it will easily run to an order of magnitude more - at best.
Once you've been through the purchasing grinder once, you will do just about anything to avoid purchasing anything every again.
So no dammit, the vendors don't need to change - the bureaucracy-ladel, rule-ridden, time-wasting purchasing departments need to!