not everyone has time to waste building their own, unless perhaps you're a kid who "got hold of daddy's credit card" and you don't have any real responsibilities.
You don't have time to spend four hours one evening assembling the parts? Not even if it saves you $1,000 off of a similarly configured prebuilt?
"if it really costs the company $500 and takes 3 weeks to procure something that Amazon could have on my desk in 24 hours for $100, maybe its not me that should be under pressure to make efficiency savings?"
Our company prices disk storage at $10,000 per terabyte. We are under a lot of pressure to do whatever we can to lower storage utilization, from deleting potentially helpful log files, to deleting data that we often find we need to recreate because somebody needed it. Some people have taken to storing critical data locally on their laptops. There is no backup of local drives. There is a backed up shared drive, but the space is limited to about 3.5 GB per person. Now I know that there is overhead in storage costs, but it seems like 10 times the actual cost of a terabyte drive ought to be a reasonable upper limit, not 200 times.
Real Programmers don't eat quiche. They eat Twinkies and Szechwan food.