As a long time Autocad user, former Autodesk Application Engineer, etc.. I have a NFR (Not for resale) version of Revit Architectural Suite 2010 and it has AutoCad, AutoCad Architecture, and Revit Architecture all in versions 2010... And they all still work.
It's not a student of trial version.. It's registered to me and AutoDesk won't provide any support for it but, there are plenty of websites that will help you out with older issues.
Ohh, and if someone hands you an Autocad drawing from a later version, AutoDesk has a program that will save it back to versions as old as 2010.
I draw floor plans and elevations for clients of houses they want to build as my primary form of income, as well as electrical schematics, piping designs, etc.. etc..
AutoDesk has the annual upgrade but, mine is so old, I'd have to start fresh with a full price deal and then upgrade every year..
I'm fine with 2010.
One thing I'm curious about is I have a version of AutoCad on my tablet that's made for tablets. Mine happens to be a Samsung but, they also have an Apple version available.
I'm wondering if I can create drawings using my tablet and send them right to a CNC router?
If you have and questions, just drop me a note.