$40m is quite affordable. I've seen not super complicated SAP implementations of GL and FICA hit $100m+... Let's not forget telecom billing systems where Amdocs easily charges $200m and up in customization.
What is this money spent on? Well, if you consider knowledge a scarce resource.... Capital is a poor substitute but all you've got when you're clueless.
I think New York spent something like $40M for a general ledger system. There is ridiculous amounts of money in these projects.