What commercial software should a data scientist purchase? I am setting up a work computer and have free reign here. My typical go-to software packages are all freely available, such as Rstudio and Anaconda. 

I have thought about investing in commercial BI software such as Tableau or Spotfire, but nobody else in the group (or myself) is a proficient user. Are there other obvious choices I am missing?

At the outset, much of what this group is working on will be exploratory. They are needing some justification to invest further into "data science".
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.