This is the method I used as well.
For the cable, I was able to source a cheap one online for like 25 bucks. The software (latest versions of Techstream) are available on any torrent search web site and works for all Toyota, Scion and Lexus vehicle, basically giving the user the same level of diagnosing and customization that's offered from the dealership).
For the pittance spent on the initial investment ($100 for the used laptop and 25 for the cable), it was well worth not having the hassle of the dealership service experience.