Software life cycle is like buying someone a puppy
I've always said that software is like buying someone a puppy. It all sounds great when you look at them, they're so cute, etc, and they don't seem to cost that much. But then you get them home and have to buy food for them, and someone has to go pick up after them.
Software is much the same way, its so "fun" to create stuff, but 90%+ of the cost is in maintaining it for the rest of its life. Many companies run in and try to save that initial money by using open source or free stuff, but then they don't realize what they're getting themselves into, in that they're also on the hook to support it and maintain it. If you could do some estimates of those costs over the life, then maybe commercial software with a support contract wouldn't look so expensive. Not to mention the opportunity cost of your people who could be doing other things.
But I suspect that many companies just go for the cheapest up front cost and hope it all works out with no plans at all for maintenance.