It depends on several factors, but I would tentatively say get it. The factors are:
1) what kind of warranty already exists. Many serious problems will be discovered fairly quickly by shooting anywhere from 1 to 100 rounds through a new gun in my albeit limited experience. if it already has a warranty that will cover these problems than it might be worth skipping. Best idea would be to look up common problems with the defective ones (all companies make a few lemons) and see if they're out-of-the box type issues or down the road type issues.
2) Do you have to pay for shipping under the extended warranty? The reason $30 seems so appealing to me for a lifetime factory warranty is that most of my local gunsmiths either charge a fee around $25-$50 just to look at a gun before adding the cost to actually fix it, or a minimum of 1 hour's billing no matter how little time it takes to actually fix, which generally runs $50+ per hour depending on the smith. HOWEVER, if you have to pay $20-$25 shipping each way to get your gun fixed under warranty, then instead of $30 compared to $50-$100 for minor repairs, you'd be looking at $60-$80 for warranty work vs local work (which will generally be much faster).
I'm a fairly cautious guy, so the lifetime warranty appeals to me, but if you would have to pay shipping both ways, possibly multiple times and wait for longer to receive your (hopefully) fixed pistol, you might be better off just leaving it be and if the need arises find a local smith that can service you for the same price.
Hope this helps the decision making process and isn't just a garbled mess of confusion.