You can get an ML workstation with 2xRTX4090 for around 10k. A 4xA800 setup tops out at 100k and should last you a few years. I consider that fairly affordable to do bleeding edge research especially compared to other fields.
We went through an amazing period of very cheap computers from 2000-2020. We just didn't need specialty or high end equipment for a while.
Now we do again.