Craigslist for a good deal? If you sell the trainer, you could probably get $100-$150.00 for it depending on which model it is. I just got a good deal on a CycleOps trainer myself, but I would have paid that much for the Magneto used.

If you won't use the trainer, then definitely get the stationary bike. I haven't ever been a huge fan of the gym machines and prefer my own bike, so I guess I made the right decision with my trainer.