Back in 2006, I spent $1,700 US on a computer I built myself to run FSX. After a great many tweaks (that never really stopped), I was lucky to get frame rates in the low 20's in unpopulated areas and clear skies, but this would easily get dragged down to the low teens, or single digits, with highly detailed aircraft, cloudy weather, and detailed scenery of any sort. It took more than $1,500 US over the years, in further hardware updates, and the release of FSX SP2, to finally get reasonable frame rates, but that too wasn't always the case depending again on how complex/detailed the aircraft, weather and scenery were at any given time. As recently as early 2019, I purchased Weather Force by REX for FSX/P3D, but after trying it I had to delete it because it dragged my frame rates too low.
Just over a year ago I bought my current pre-built system, as seen in my signature, for $1,800 US, strictly with MSFS in mind (granted, it was on sale at the time). I have included it in my signature because I had more than a few people ask me what sort of system I use (though I have thought of removing it from my signature every day since). Without any tweaking, this $1,800 computer has been running MSFS at Ultra settings with an average/mean of about 40 FPS with the FPS uncapped, and this of course can reach into the 50's or dip into the upper 20's/low 30's. I have my FPS capped at 30 through my Nvidia settings, but that is more to do with trying to keep my graphics card running cool (ever since overheating with P3Dv5), and I never notice any stuttering, it just runs solid, no matter how complex/populated the weather gets, or how detailed/populated the scenery is, my mind never has to think about FPS, as there is never an indicator of stuttering or choppy performance (that was never the case with FSX or P3D). Even when flying into the densely-packed, cloud-filled hurricanes this past summer in MSFS, I never noticed a performance drop. I don't know what a reasonable computer cost/price is, but I've seen people building PC's for flight sim use that cost twice as much, even going back to FSX and FS2004 before it (not sure how much more gain they get, though). I remember back to the summer of 2019, when there were some (a few of which I distinctly remember) who were speculating how no one would be able to run MSFS with good performance at all until maybe a year or more after its release, once computer hardware had some time to catch-up, and that what Microsoft was showing was all just smoke and mirrors - that sure didn't turn out to be the case.
One of the things I've been reading a lot recently, from those that get a kick out of trying to bash MSFS (some in the DCS community - not here), is about how it is "just a scenery simulator". The scenery in MSFS is what I've been dreaming about since starting flight simming 20 years ago. It's what finally makes flying from point A to point B fun, enjoyable, realistic and worthwhile. No more flying over the same boring generic fields, tundra or city textures, repeated endlessly, or unrealistically spotting airfields 20 miles away due to those large, straight-edge geometric patches of green that dominate airports in FSX/P3D and X-Plane. Despite having been using MSFS since April, I am still incredibly amazed every day I use this sim that I can choose any point in the world and have the type of scenery accessible as in this sim, and not having had to spend hundreds or thousands of dollars for it. It is also the first time ever in the history of flight simming that my region, where I live and now enjoy virtually flying the most, has ever received such detailed and accurate scenery, most of it covered in photogrammetry besides. Before MSFS, I usually completely avoided flying around my local area, but now it is by far the one area I fly the most, and not just around my local community/airport, but cross-country flights all around my state and neighboring states - each visual journey and destination fully unique from the last. I also get a tremendous amount of joy flying out to and exploring historic sites, battle fields, archaeological dig sites and geological history all over the world using this sim. As far as scenery addons go, it would seem to me that, not even 4 months into the release of this sim, there are already more freeware scenery and airport addons released for MSFS than there ever has been for FSX/P3D (that might not be true, but it sure seems like it). I have 11 scenery addons installed just for Minnesota, which is more than double the amount I ever saw for FSX/P3D, and I have over 300 freeware scenery/airport addons installed world-wide - which I don't believe even comes close to half of the amount of all of the scenery/airport addons that have been released to-date.
The flight dynamics of the 30 default aircraft in MSFS are better than most payware for FSX & P3D, and are comparable to the best. I don't know that there is any difference, that I can tell, between flying the default MSFS Cessna 172 compared to flying the FSX/P3D A2A Cessna 172 - though the cost factor is quite substantially different ($4 for the default MSFS Cessna 172, if you take the 30 default aircraft divided by the cost of the Deluxe version of the sim, vs. $50, $70, $80, $99 or $800 for the A2A 172, depending on which purchasing option you choose - though personally, I hate that apples to oranges comparison). The ground friction modeling and atmospheric modeling in MSFS is the best I've ever experienced in any sim. The exterior and interior visuals of the 30 default aircraft in MSFS are better than, or at least comparable to, the best available for FSX/P3D, anyway you want to look at it - accuracy, level of detail, realism, etc. The sound suites for the 30 default MSFS aircraft are better than any I've experienced in FSX/P3D. I get it that some really only get enjoyment out of simming for making repaints and the attention and satisfaction it brings, and right now there aren't that many aircraft to choose from to make repaints for, yet, but again, we haven't even reached 4 months since the sim was released.
Having been as much a fan as I have been of the default aircraft, I'm personally really looking forward to any of the further payware aircraft and helicopter addons that ASOBO will be releasing themselves, knowing the level of quality and detail they work towards. Scenery and aircraft selection aside, MSFS has everything that default FSX or default P3D has to offer, and an incredible amount more.
BTW, MSFS made it into Popular Science's top 100 innovations of this year. I don't recall any other flight simulators ever making such a list?