As stated in the article; "Soldering lead wires to the thermistor, with a bit of heat shrink tubing (4' - 1/8" dia. ~$0.50) or tape to insulate the soldered joints, is about all that needs to be done."Heatshrink tubing is slid over the wires before they are soldered, and then positioned over the exposed metal after soldering is complete. Heating of the tubing material (hair drier / lighter) causes it to decrease in diameter, encasing the wire and thus insulating from possible shorts. In the image below you can see a finished thermistor after the leads have been insulated. This can also be accomplished easily with electrical tape as well. Bare leads in close proximity to a processor could be a recipe for disaster if they happen to short out a component.

3) Why spend the money on a used battery instead of getting new thermistors?

Well, there are a couple of reasons. From our position in Canada, ordering thermistors from the source we quoted it just too expensive for more then one or two. The least expensive ones are $6 US @ 1.56 exchange is about $9.36ea. not including shipping, taxes or minimum order restrictions. We currently have six thermistors  salvaged from various equipment in use. That translates into $56.16 we didn't have to fork out. We paid $6 US for the laptop battery in the test and got two thermistors for it. $3 a piece is a pretty good deal for thermistors. Also, some people may be fortunate to have an old laptop battery lying around doing nothing, or know where some are being sold off for a few dollars each, and could potentially use them. Lastly, Recycling - its good for the envirnoment too!

4) Affording the test equipment used to save a few bucks on a thermistor.

There wouldn't be much point in getting a digital multimeter just to test thermistors. If one is available, its a great way to test thermistor compatibility. If a multimeter isn't readily available there were a couple other ways we pointed out to test compatibility. 

As an aside, the point of the article is not really about what is affordable, it was intended to show an alternative to commercial avenues for getting thermistors. There are many articles out there which will tell you the exact part numbers to buy from Radio Shack in order to make your thermistor. www.bxboards.com has a really good write up if anyone doesn't feel like tackling this kinna thing.