AutoCAD is not the equivalent of SolidWorks.
Autodesk Inventor is the equivalent of SolidWorks.
Then you need to consider what version for doing the work you describe. Base Inventor or SolidWorks will probably not do all you want to do.
I recommend you add an equal amout for training. Therefore if you budget $7.5k for the software budget another $7.5k for training.
Students can download Autodesk Inventor Professional for free from http://www.autodesk.com/edcommunity They can then download Inventor Tooling and also AutoCAD and MDT.