I've tried quite a few closed back cans around the $3-500 mark and none were anywhere near as good for sound stage as open back. The only pair of closed back I have ever had where I would consider them to be almost as good as my Grado RS2E for that is my T5P and those are a thousand dollars.
If you are really super picky about your sound then the best pair of cans I have heard for detail in that price range are my RS2E, though note you will sacrifice deep down grunt. But for classical music or anything where you really want the detail they are the best I've had.
However one thing I will say? I could easily live without all of the other headphones I own now, apart from my RS2E and T5P. So like with computers? spend as much as you can. Get as high up the chain as you can, instead of making stops on the way there.
There's a big difference between audiophile gear and computers.
Unlike PCs which you can customize along the way and upgrade as you like, audiophile gear is pretty much do or die - If I didn't like the e10k or the current cans I own, I'd have to go ahead and resell them for a loss and then pay more for a different product.
Also, I do believe that going slowly in several tiers trains your ears much more than just getting a pair of 1500$ Audezes after you've used the stock earphones you got with your smartphone.
I remember the first pair of audio gear that got me into it was my first "real" IEMs, the Vsonic VSD3S.
Used to use cheapo 2$ ebay earphones or box earbuds for audio OTG since I was born until I turned 17 and got my first IEMs after a friend recommended them. Difference was INSANE, and I going back to the cheapo stuff when my Vsonics' cable went bad was awful.
Later on I got the HD598s and that was another step, then the DAC helped me improve further, and frankly going through with using different headphones and earphones I can say that it FEELS like I trained myself to notice more details.
For example, small details I couldn't hear via the VSD3S or even my car speakers for example are stuff that I can hear much more clearly nowadays.
Something that I didn't say but should - I was researching the Ebony TH-X00 when I saw the most recent drop (the new detachable cable version) and saw a lot of people complaining about the lack of difference between something like the hd700 to hd800 or similar top of the line audiophile devices compared to price points.
This is mostly why I decided to keep the bar at ~400-450USD for the most part. I'll just get another tier up with the audiophile gear, next step would be separate DAC and amp, something that could probably be able to power more expensive cans and also improve the quality of the current ones up to the upgrade point.
But until then, seeing as I'm not a music producer or spend hours each day just sitting there listening to music, tiers it is.