What commercial software should a data scientist purchase?
If you are looking for a technical package I would definitely go with Mathematica. It has functions for a very wide range of disciplines that come standard with it (no extra packages to buy). This allows you to expand into techniques as you grow without having to change platforms or buy extra packages.  It also has a great interactive format in CDF with both a free and professional reader. The documentation is interactive as well which really helps a lot.

However, you have to be open to a little bit of structure, typing &amp; chaining functions together, and things like this.  Once you get started it comes very quickly.