Was talking to you wishing you wrote that in first place- constructive and good question
And that is really good point- the price of PC. It really matters of what headset you pick. By your talk you have experience with old Iphone. Is that same Iphone from shop where you bought cigarettes? Im very sorry about your bad experience That is where your negative reaction about VR might coming? I would highly recommend you to try Oculus rift or HTC vive or any other 2gen headset or if possible ( rearly ) try new headsets like Pimax with 4k/5k/8k resolution. You will have clear picture of what actually VR capable of. There lot of malls with such places where you can try VR.
Returning back to PC specs you need, you can check apps on official sites of Oculus and Vive that they provide to check your pc for specs if its VR Ready. But honestly I had old pc with old gtx970. And it ran almost all vr titles that I played. Vr is very demanding on card as it doubles the screens. Also have to keep up the 90 fps or your brain goes 'No no nooo!'
If your PC doesnt meet recommendations it still can keep those 90 frames by reprojection ( its basically adds extra frames ) for more
info from reddit
But if you got lowend pc it surly doesnt mean you cant use your pc for gaming. By that i mean you can play othergames that are not that demanding. And theres a lot. Beat saber for example can be played on phone VR. If its not demanding game doesnt mean you wont have fun by playing it.