You should look at how the new low-cost high speed trains is looking now in Spain. The high speed rails are now open to the market and a Madrid-Barcelona ticket would be around 10 EUR (12ish USD) and a 2:30h trip. https://www.ouigo.com/es/en/barcelona-madrid-train

I really look forward to this deregulation (it was about time for Renfe to have real rivals) and I think it will be a huge added value for the people, that Spain has the second longest high speed train network in the world. I guess we'll see how it evolves in around 5/10 years...