Experiments like Wendelstein remind me that the only thing holding back fusion power is money for research like this. Every year, we spend billions on fossil fuel exploration because the return on investment is quick - just think about all the wells going in to extract shale oil. What if we collectively had the will to invest this much into fusion?
On top of what everybody else has said, I also don't think it's a given, even if/once we crack the technology, that anybody will actually use it to generate power. I think there's a totally plausible outcome where somebody builds a fusion reactor that produces more energy than it consumes and said reactor has essentially infinite, essentially free fuel, but the design they come up with costs $20 billion a pop to buil…
The issue is the design of extremely specialized components, not necessarily the raw materials (except when they're novel superconducting magnets designed for that purpose).
I think schedule delays are what is making ITER so expensive.