Over the years, I’ve bought 3 used CycleOps spin bikes with Power Meters all for under $500 each.
That provided the best match for the real world forced that I saw at the track that I could replicate in my home or gym.
One season, nearly 100% of my training was on a spin bike and it worked. Kevin Mansker was also reported to do most of his training on similar spin bikes when he was in top form.