The vast majority of real estate deals are handled by title companies and attornies for a good reason... because it can be a complicated job to get all the documentation right, make sure the title is clear, facilitate the transfer of funds, and deal with any legal issues that may come up in the process. If you're talking about a house, commercial building, or anything with a value higher than $10K... I would say it's pretty smart to leave this job to a professional closing agent because they'll do the job better than you, and it'll save you a ton of time (i.e. - it's very much worth the added cost and time in getting the deal closed).
However, if you're talking specifically about a vacant land deal, with no financing involved, on a property that is very cheap, that's when self-closing starts to make sense (assuming you know how to do your own title search, fill out the documentation correctly and communicate with all parties involved, etc). If you want to go down that road, this blog post may be of help.