I thought the A800 was pretty good for what it is--but the comfort was bad, at least in my case. It also was more or less duplicative of other headphones I had on hand...so I sold it.
Others on Head-Fi have way more experience than me w/inexpensive and mid-priced open back headphones. Still, a couple suggestions:
1 - AR-H1 Planar Magnetic Headphones: Massdrop is having a drop for Acoustic Research planar open-back headphones @1/2 the usual retail price (Massdrop price is $300). I haven't heard these, but I did some reading on them yesterday. Description of their sound seems fairly close to what you're looking for. Regardless, I'm a real open-back planar lover, and this looks like quite a deal. The only issue is that this HP might need more power than the usual dynamic headphones:
https://www.massdrop.com/buy/acoustic-research-ar-h1-planar-magnetic-headphones
2 - Akai 50X Professional w/extensive mods by @Slater : It's a long story, but this Head-Fi'er (a very talented & knowledgeable modder of headphones) took the basic Akai 50X (a somewhat warm, bassy closed-back ChiFi design) and turned it into an open-back headphone for me...the result was considerably better treble and resolution than stock. I have no idea what he would want for one of these...whatever it is, I'm guessing it's within the range of what you paid for the A800s.
Here's a link to my review of the modded Akai 50X:
https://www.head-fi.org/showcase/modded-akai-professional-x50-vs-stock.23127/reviews
3 - E-Mu Teak: These are closed back. They have terrific bass, also some sparkle in the upper mids/lower treble. I liked them a lot. Sold mine only because the pads bothered me (and pad-rolling was difficult). Others on Head-Fi report good results w/this or that aftermarket pad, though. You can get these new for ~$399, either on Massdrop or direct from the mfr in Singapore. I can get you his email address if you like.
4 - 1More H1707: Another closed headphone. I've never heard these, but some on Head-Fi rave about the. The descriptions of sound I've read sound suitable for your tastes. These are on Amazon/US for $230.