From what you've described (that this will be your ONE machine), I'd have to say do not even think of getting a serger.
1. They do only one thing, and it isn't the thing that you'll be wanting to do most of the time.
2. They're REALLY hard to get used to, have impossible thread feeds and when they fuck up (which can be often) it can really mess up your piece --- because it cuts off a piece of material with each pass. If it malfunctions and you have to start that line over again, you're cutting the piece smaller than it was intended to be.
3. To get the straight line of sewing in the seam that was shown in DAB's picture, you need to have a 5-thread serger. The 3-threads do only the outside part. 5-threads are not only way more expensive, but WAY harder to thread properly. The threading is a nightmare. Believe me!
That said.... Getting a good machine with a goodly selection of stitches is really all you need to start out with. You can "serge" the edges to ensure a moopless finish using one of these specialty stitches. Zigzag will do better than nothing, but "Overlock" is best (definitely try to get one with this stitch!!!). It basically does the same thing as the serger would do, but without cutting it flush. You just have to be really good at staying right on the edge.
Here's link where someone took the time to draw in the stitches: http://www.dummies.com/how-to/content/m ... r-you.html
It might be helpful just to have the visual when choosing your machine.
$400 will get you a really nice machine.
Make sure you google a potential model before buying it. Even the older ones. Some seemingly solid metal machines have plastic cogs that are known to be problems down the line. These can mean costly repairs and real headaches during a sewing session.
My best machine was bought on Ebay from a guy who refurbished old machines. A Toyota from the late 40's, It is absolute perfection and will go thru thick leather and silk alike. Under $200
My worst purchase (tho I can't give it up because I've now grown to love it) was my serger. Industrial with no threading chart, it took me eons to learn how to get it to work with 3 threads. I've yet to thread the 5th properly, rendering the 4th useless. Since I bought it from an individual who hadn't used it herself I have no idea if the problem is me or the machine, and would have to pay to have someone come in to check it out (it being a huge, unwieldy and about 500 pounds of table and machine).
I would never suggest buying a secondhand serger to someone who's never used one before. Really. Paying the same amount of money (or less) for a used industrial machine as a new plastic one from Walmart may seem like a really good idea, but you have to consider your own knowledge and skill level before making that move. It can bite you in the ass later. For a Serger. For a regular machine, you can get amazing deals on a really good quality machine for less than you'd pay for a cheaper one prone to meltdowns. Just make sure you get it from someone who really knows machines and stands by their word.
And really. Google the model first for known issues. Take your time in selecting the right one.
And then enjoy the hell out of it.Edited to say: Get a machine with an overlock stitch. Do NOT get an overlock machine. That's just another name for a serger.