I mean, sure - if I want to make sure my staff have a word processor and a spreadsheet, I'm going to buy Microsoft Office rather than writing it for myself. On

I mean, sure - if I want to make sure my staff have a word processor and a spreadsheet, I'm going to buy Microsoft Office rather than writing it for myself. On the other hand, for enterprise software, there's usually some seriously non-trivial integration cost - particularly if you're not starting from a green field. So the problem is "you can't buy a solution - you just need to decide how much of it you're going to build yourself according to your needs, and how much you're going to buy and tailor/integrate."