It's actually super easy to analyze this.
The first and important question to ask is... does a PS5 pro cost Sony $100 more to make than a PS5? Please note, the question isn't if the PS5pro cost Sony $$$ to make, it's if it costs them $$$ more than a PS5 to make.
I think this is what has people quoting strange prices, they aren't looking at this from a BOM perspective.
eg. If Sony currently spends $80 on a PS5 slim APU. Then they would be spending around $120 on a PS5pro APU. That is not $120 more expensive, it's only $40 more expensive. Then take the RAM, if Sony spends $60 on PS5slim RAM, then they could be spending $80 on the PS5pro RAM (same amount, just faster), Again, this is not $80 more than the Slim, it's $20 more.
And after you have done the RAM and APu, you will quickly realize that sony is not changing much else in the Pro. Its literally a PS5 Slim, but with a better APU and faster RAM. Thats it. Hell, the PSU that is currently in the Slim is likely powerful enough to handle the Pro. Oh, and more heat sinks. Those are the three things being changed here. APU, RAM, and heat sinks. Maybe throw in a bigger fan?