You'd be luck to tell what anything was in an MRI scan from 20 years ago. And if you could it's because the scan took an hour.

As someone who works in MRI research, the current technology is quite new and cutting edge. Building and maintaining the machines is quick expensive.

All that said, the cost for a scan here in the states is way overly inflated. MRI scanners are generally profit leading centers in most hospitals, this is despite their large operating cost. If that doesn't tell you where your money is really going.

The speed of sound happens to be much higher in solids. The more rigid the material, the faster sound will travel through it.

That's because you are moving. Per Maxwell's laws changing magnetic fields induce a current. If you move your head too quickly through them those tiny currents can be induced in your inner ear resulting in the nausea.

I work in the MRI field on the engineering research side of things. Those sounds a lot like MRI scanners. The 7T scanners are notoriousness for inducing nausea when moving in and out of them because the field drops off and grows so quickly around the scanner. I've never heard of nausea being induced from a 3T before though. Maybe I just haven't been moving around fast enough inside it.