Wood working tools can be expensive and not all brands are created equal, so it is always important to do your research before making a purchase. A cheap saw, for instance, will likely not give you cuts that are as clean as a more expensive model. If your work requires that you cut wood regularly, you are going to want a saw that not only gives you excellent cuts, but also that will be reliable and last a long time.
There are a number of resources for those who do not know a whole lot about the industry. Simply running a few searches on the internet will help you to familiarize yourself with the different models and styles of saws that are available so that you can figure out what will work the best for you. Again, the last thing you want to do is cut corners (no pun intended) when it comes to this sort of thing, so you want to be well educated in regards to this sort of thing.
There is, of course, also the issue of price. You might be able to find table saw for a little over a hundred bucks, but that does not necessarily mean that it will be the best portable table saw for you. The top of the line models will typically run you closer to fifteen hundred or two-thousand dollars, which means that quality is a lot more expensive than something you are going to use once and then forget about.
Basically, if you are just doing one small project, you can probably get away with a cheaper model of table saw. If, however, you need something that is going to be sturdy and be able to handle larger jobs, you definitely want to make a bit of an investment.