I believe you might enjoy these:
https://hifiman.com/products/detail/267
Yes, they are at the upper limit of your price range, but they fit ALL of your criteria. The treble is open, airy, defined, but NOT fatiguing. The sound stage is WIDE and the instrument locations are stable and well defined. The vocals (both male and female) are sublime, as in wonderfully smooth and articulate. The bass goes deep and has good body, but with not as much detail as others.
My second recommendation would be these:
https://hifiman.com/products/detail/312
Again, treble is amazingly open and airy, with excellent sound stage that is wide and well defined. These are a newer model than the above (He1000v2), and the bass on these is a little better as far as detail goes, but not as much bass.
Now, here's the deal, I tried both above headphones (Arya v3 first, the the HE1000V2 later), and really liked them both, but ended up with a pair of Audeze LCD-4 headphones, so why am I recommending the Hifiman phones? .
First I LOVE the LCD-4 phones, they just work for me, but they also require a LOT of equalization to get there, and they still don't have the top end air and resolution of either of the Hifiman phones. And yes, I do miss that, but, the LCD-4 headphones have BASS that is both plentiful AND extremely detailed, and (when Equed) a wonderful midrange and vocal presentation. However I know that I'm missing some of the treble details of the He1000V2 or AryaV3. It's a tradeoff that works for me. I've been playing standup and electric bass for over 50 years, so that's VERY important to me, and the LCD-4 gives me what I need.
Of the 2 Hifiman models, the HE1000v2, has the best non-fatiguing treble, with simply outstanding midrange/vocals and near perfect instrument presentation (with no EQ), while I found the AryaV3 to be just a bit aggressive and tiring occasionally in the treble. And, while the HE1000V2 had more bass, the quality of the bass, the texture and detail, and depth, was better on the AryaV3. Personally, if I had to choose between the 2, it would be the HE1000V2, with midrange and treble nearly perfect, and very good bass.
Here's what's nice, you can try out either one for 30 days and get a full refund if you don't like them, and when I got mine from the Hifiman Store, there was no added sales tax (not sure if that's a state by state thing or not).
Anyway, I hope that helps. Good luck on your journey. Do spend some time reading these forums before spending any money, as there is a LOT of good information here and helpful folks. Just remember that we all have our own biases and expectations, plus, we all tend to hear things a bit differently, so just make sure you have a good return policy when you try something out.
EDIT: By the way, I auditioned all these using my Topping D30Pro into the Topping A30Pro, so very similar to your setup : )
