GREAT QUESTION
...
[ON soapbox 
] I believe funding is likely the biggest challenge most FIRST teams face to remain viable, and purchasing additional Inventor licenses is just NOT an option. While I am sure Autodesk contributes significant money and resources to FIRST on the corporate level, I think they fall woefully short in supporting the individual teams. As has already been mentioned here, some teams are affiliated with schools that have well equipped technology departments, or programs like PLTW, which already have a classroom full of Inventor/MAX licenses available for use. Unfortunately there are many teams which do not have these tools readily available, nor can they afford the high cost of adding additional seats (although I did find a student/education version for only $134.95
here). My beef with Autodesk is that once the media (CDs) is distributed to teams there is NO additional cost to the company to provide multiple registration keys. I think 6 per team would be a reasonable amount. They actually BENEFIT from providing more exposure to future engineers, who will later enter the workforce and become potential customers.
The single seat license they now provide is, in my opinion, worthless. If a team already has the resources, they don't need it (except to maybe load onto a teacher's or engineer's laptop). And if they don't already have it available, one license is not near enough to accomplish all the tasks required for the 6-week design/build of a robot, and entry into the Autodesk competitions, while on a steep learning curve.
[OFF soapbox ]
C'mon Autodesk ... STEP UP!