My alternator decided to stop charging the other day. The dreaded red warning message showed up intermittently for a few days, after which it became permanent.
I suspected the regulator, so I got under the car and removed it through the back.
Tiny screwdriver and nut driver were extremely helpful.
One of the brushes was worn out and wasn't making contact anymore.

Original regulator would have cost me $148 + tax at the local dealer.
I found the same part online for $50 and up, including shipping.
Decided to keep looking.
I contacted some local alternator rebuilders. One of them offered a VR (not Bosch regulator) for $25, and a free brush to replace the broken one.
I fixed my old regulator and installed the VR one.
If you're facing this problem and you have one type of regulator (in my case Bosch), don't be afraid to try a different one (like VR), as long as it fits mechanically.
After all, they all perform the same job: adjust your rotor current so the charging voltage stays between 13.5 - 14.4V. The only variable as far as I can tell is the current driven through the rotor.
I hope this helps someone.
Tudor

Did mine about 2 weeks ago.
Mine was $25 also.
However the VR brush combo like pictured can be had at a better price if you look.
This is cheap an easy insurance to avoid a break down.



Here's the old one and the new one.



Here's the old one in the alt.
the slip ring looked fine and seemed to be perfectly round.

Thanks for sharing your pictures. I'm usually in a rush when I work on my car, and I never think of taking any pictures.