Build versus Buy
My preference in these situations is always to start with buy, and then try to justify build.  Unless it's a core competency to your own business, which it almost always isn't, it makes sense to let someone else do it better.Their profit margin is usually in their efficiency in doing it better than you, and at the same time you get the benefit of all the features they add for other customers.Oftentimes the decision to build usually came down to the difficulty in integration of a commercial product, not the cost.  In most cases the cost is set to be competitive against building yourself.Except in the case of Splunk.  Their pricing is ridiculous.