Sorry I don't remember off the top of my head I'll have to go back and watch that episode again.
Regarding high compression being more expensive... I'd argue it is because if I had wanted more than 9:1 in my current 5.9L Magnum with open-chamber Edelbrocks (long story) I would have had to swap out the pistons which obviously would require new rings and the cylinders honed. Instead I just used a junkyard short block as-is with new rod bearings and "sent it". Took advantage of the fact that the used heads I got came with ARP studs and I added Cometic MLS gaskets so it's ready for some light boost if I ever want it. Runs pretty damn good as-is I'm still in the process of upgrading the rest of the chassis to really make use of the power. The cam is a custom-grind Racer Brown hydraulic roller which I know also helps a lot with the rest of the combo. ~6000 miles since I built it and it's still "tight" no real blowby or any other indication of bottom-end wear.
Conventional wisdom would say it's stupid to put a $3000 top end on a $200 short block but the junkyard Magnums seem good for it.