I literally just dropped £4,099 on a fully loaded MacBook Pro 16" with those specs. I could not be happier. Its going to be a great daily driver for many years to come. Also the construction is A+ and solid, makes my 2015 MacBook Pro feel cheap in comparison.
I spent about £3k on a 14" with 1TB and 32G and I'm very very happy with it - the experience is just ridiculously better than the older 15" MBP I had - or any of the x86 laptops I've used recently too - it has a good screen, a reasonable keyboard, a good touchpad, it's much faster, quieter, has better battery life, and is more portable without losing a lot of screen space.
2 TB of NVME storage is little more than $200 off-the-shelf. 64 gigs of DDR4, high-bandwidth laptop memory costs ~$250. Even assuming Apple is springing for high-quality, high-speed RAM, $800 borders on insanity when other laptops offer similar configuration options at less than half the price. Apple's price gouging in this department is well-documented, I don't think I need to argue with HN users about that.
$250 will get you 64 GB of laptop memory but that will be operating at something like 1/8 to 1/16th the bandwidth. Similarly you can get 2 TB of NVMe for $200 but you need to go to the ~$350 range to approach the bandwidth, I haven't looked into IOPS.
I still think the prices are inflated over raw hardware but not as exaggerated as finding the cheapest parts with the same capacities would make it seem.
I just checked out some random Dell Precision laptop. They want $800 for 64GB RAM and $720 for SSD. Seems pretty comparable to me. Samsung 970 Pro 1TB is $270 on newegg, so it makes $540 for 2TB. Cheaper, but it's only PCI-E 3.