Something to keep in mind before you spend a lot of money. This is the total time it takes to perform a completely automated, start to finish post-process of an image. So, your computer took 90 seconds to perform all of that processing, one process after another, back to back. A minute and a half.
How long does it take you to process an image? A minute and a half? If you say yes to that, my head might literally explode! I'm going to assume it takes you...at least 30 minutes? Longer? An hour...two hours? With the kind of processing involved in the benchmark, I would say a lot of imagers, including myself, would probably take an hour to do it all.
SO...take that 90 seconds, and distribute all that processing time out over 30, 60, 90 MINUTES of total time. Do you think you are going to notice the difference in how long it takes to, say, do a sample pass of noise reduction on a small preview with TGV, between the system that gets the benchmark job done in 53 seconds vs. your system which gets it done in 90? How much difference in time to run, say, MMT do you think you would see with the faster build? Maybe a second? Two?
Do you think you would even notice a 5 second difference in how long it took TGV, or MMT, or HDRMT, or any one of those other longer running processes, when you were actually sitting there fiddling around with settings and figuring out how best to handle your data?
I use an "ancient" i7 4930k CPU, overclocked a bit, with 32gb of "ancient" DDR3 overclocked a bit, on an "old" SSD (not an M2) for the OS, with a similarly "old" SSD for data storage. Since PI got multi-threaded capabilities in its pre-processing tools, I have never felt that PI was slow. By far the slowest part of PI was the pre-processing, which when it was all single threaded took FOR-E-VER!!!! But now it blitzes right through all the pre-processing stuff, and lately I'm down to integrating 40, 50, 60 frames per channel, for a total of less than 200 most of the time, which has made it all go even faster. Once I am into the actual post-processing? The single largest bottleneck...is me. When running HEFTY processes like noise reduction, deconvolution, etc. I always do it on smaller previews to start. So the time to process is just seconds anyway. I then will fiddle around with the settings and re-apply to these previews over, and over, and over and over and over...until I have it all "just right". Then I'll apply it to the full image, which might take about a minute to process. I'll easily spend 10, 20, 30 times as much time fiddling around and getting things just right, than the amount of time PI actually takes to compute. Then I'm onto the next phase of processing, where I'll do the same thing...fiddle around until things are just right, using previews to speed things up, then apply to the full image just once.
I haven't upgraded my computer in some five years. PI does not feel slow at all. It isn't "instantaneous" for everything, but...look at the benchmarks. You've got about 40-50 seconds for high end modern windows rigs (expensive rigs!), vs. 90 seconds for your rig. I mean, at best, spending a lot of money on a new computer for PI might speed up the things PI itself does by a factor of...two? If you go the Linux route, and get one of the higher end Ryzens with lots of cores, you MIGHT get down into the 20 second range. That would be about 4x faster than your rig...but again...for the things PI itself does. That...minute or two of compute time. Out of the entire post-processing workflow that will usually take...30, 40, 60 minutes, if not longer.
Just to shed some light on what it is you would actually be spending your hard earned money on.