Volumetric light cones

I want to have a volumetric light beam on my spotlights so you see an actual light beam in game. This is a very important element for a project I’m working on for school. The atmosphere of the game I’m developing is about the dark and the spotlights.

Unity does not have built in volumetric light effects except for Sun Shafts. The Sun Shaft effect looks good but only supports 1 light source.

The alternatives I found are:

Volumetric Light Beam Kit

This is a $40 Unity package that does create the desired effect with a cone mesh and a shader. However this package has been deprecated and cannot be purchased anymore
https://www.assetstore.unity3d.com/en/#!/content/3559 

Sunshine!

This must be the best looking lighting effect that you can buy at the asset store, however it comes with a price tag of $95. This is way too expensive for a student project. https://www.assetstore.unity3d.com/en/#!/content/10153

Light shafeds

This was the best solution that I could find. It’s a public domain package that creates the exact effect I was looking for.
https://github.com/robertcupisz/LightShafts

The only problem is that this effect stacks with multiple beams so it still is not the volumetric effect that I’m looking for.

Light shafeds effect stacking.

Unity announced a volumetric light effect that will release in June 2016 with the Unity 5.4 release. I think I will wait for that since it’s a really complex effect and I don't feel experienced enough to build my own volumetric light effect.