What AMD is doing is really insane in my opinion. I'm not sure if they are pricing their processors low on purpose and/or if they have found a way to manufacture cheaper and/or Intel was screwing consumers with their pricing since they were so dominate.
No matter what, AMD is able to provide something that is measurably better and significantly cheaper than the incumbent, and if the blue ocean strategy holds, they should become the new incumbent in the near future.
So yes, they figured out how to produce cheaper solutions.
For EPYC, AMD is using nine chips: https://images.anandtech.com/doci/13561/amd_rome-678_678x452...
That's 1x I/O chip (kind of like a router), and 8x chips, each of which has 8x cores on it. Total for 64-cores / 128-threads across 8-compute chips, talking together through a central 1x I/O and Memory chip.
The I/O chip is the biggest for reasons: 1. Its made on a cheaper process. 2. It has worse performance than the compute chips. 3. Its required to be big because driving external I/O requires more power.
So the I/O chip can be made on a cheap / inefficient 14nm process, while the CPUs can be made on a more expensive 7nm process (maximizing clock rates, power-efficiency). The big I/O ports are going to eat up a lot of power regardless of 7nm or 14nm process, so might as well save money here.