I'll weigh in as a vote for DSA.
There is no question that many a fine rifle can be found for less than a cost of a DSA SA58 or even STG58. On the other hand, the parts compliance and overall soundness of such rifles is questionable. In other words, you may get a fabulous rifle, you may get a junk rifle, or maybe just a rifle that is felonious to possess...certainly going with a rifle built by one of the established smiths is preferable to buying a mutt from just anyone.
Similarly, if you are so inclined, you could probably build your own decent rifle for far less than a DSA.....
That having been said, I believe in Murphy's law...if it can go wrong, it will...I'm not suggesting that DSA is impervious to "issues" but I am suggesting that it's a hell of a lot easier to deal with an established company who built my rifle from the ground up rather than someone who merely assembles my parts, or merely sold parts I had assembled...such an approach leaves you open to passing of the buck, pointing of fingers, etc. If my rifle has screwed up, I know who's fault it is....DSA's.
That having been said, my rifle functions flawlessly and looks terrific (as it should for such a steep price tag). Personally, the peace of mind and the quality rifle I got when dealing with DSA was worth every penny. My experience both with the DSA product and the customer service has been top notch.
EDITED TO ADD: I will note that I was told to expect a wait of at least 6-12 weeks in taking delivery of my DSA but it was delivered, including custom barrel cutting and brake repinning and the addition of carbon fiber handguards within about 2 weeks.