His lab would cost a fortune if you were buying the equipment new from the manufacturer. But he has been able to source a lot of decommissioned semiconductor fab equipment through eBay and donations etc. Like his wire bonding machine. He has spent years of effort setting it all up, so it's not something for a one off project.
But replicating his simpler transistor experiments should be doable on a smaller budget. Also check out Jeri Ellsworth's DIY transistor project. Some nasty chemicals and special equipment is necessary but nothing too much for a hobbyist.
I don’t know the minimum amount equipment needed to make these chips, but his garage is stuffed with old but still expensive equipment (if you need to buy it on eBay.) Things like a wire bonder, an electron microscope, a vacuum chamber etc.
I think that most of these were donated to him though.
Also roughly, would anyone know the cost per batch of chips? I’d love to run thing as a learning exercise for middle or high school students and wonder how costly it would be.