I am an engineer who has studied both spaceflight dynamics and electro-magnetics at the graduate level and in my opinion this idea is largely impractical for two reasons: it will require insane amounts of energy to operate and will be extremely unstable. The forces involved in moving a mass at orbital speeds will make sending a rocket down a tube basically impossible without it impacting the walls or creating high G-forces on the rocket. The amount of energy required to suspend the track in the air is also incredible and is way beyond our ability to generate practically. However, this idea would actually work pretty well on the moon where there is no atmosphere. An interesting approach is to launch only people into earth orbit and build spacecraft on the moon where it is easy to launch into orbit. It will still be expensive (although less-so with simpler rockets like SpaceX) to put people into Earth orbit but it would be cheap to launch equipment off the moon.
Edit: few more thoughts...
1. Once you are in orbit you can use something like VASIMR that is nuclear powered and mass efficient but doesn't have the thrust to get into orbit.
2. Rockets are expensive because each one is effectively a prototype. If economy of scale ever gets going and some reasonable reusabillity is implemented the price should come down.
3. Fuel is only 2% of a launch cost.
4. The shuttle program was a technological disaster that made getting into space way more expensive than it should have been.
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