[jhgb]

The real question is how much material you'd need for a ~80000-km-sized vertical structure that the lunar elevator is expected to be. The ~1:1000 factor in the largest dimension required can't be good for a practical elevator.

As for the track, I suspect it might be (order-of-magnitude-wise) similar to existing maglevs on Earth. On one hand, you need to reach higher velocities, higher precisions, etc. On the other hand, any supporting structure can be substantially more lightweight (much smaller gravity, no corrosion resistance required, etc.).