I've been looking for used/new mirror less and I'm pretty sure I've gotten crazy because of it.

As someone who's into amateur photography and astro (been taking constellation pics ever since I remember getting a capable enough phone), got a beginner telescope to see the moon through, I've decided it's time to upgrade and treat myself a little.

Told myself - hey, there are plenty cameras online, I'll definitely find something for a good price! Oh how wrong I was...

Used? New? DSLR? Mirrorless? If yes, what crop? 4:3? Do I really need a fullframe? Which brand has cheaper lenses if I ever want to shoot something else too? Which brand has the most beginner friendly UI? Do I need to worry about the UI at all? Canon uses some new mount, does that also play a role? How high of a shutter number is too high? What type of lens? What f number? What mm number? It just becomes too overstimulating...

First, I tried attacking my local astrophoto discord with questions. Didn't get much advice besides - just get the most expensive camera and you'll be set, then invest into a tracker. Jokes on them, I don't print money at home. Another choice was a dedicated astro camera like the Dwarf, but those don't feel right to me - I'd also like to use the camera as normal, such as landscape photography.

I'm at my wit's end, so I'll try my luck here.

• beginner astrophoto. no need for deep sky objects or something crazy. Mostly bright nebulae, milky way, Moon, Jupiter, Saturn(?) and constellations.
• I'm in Bortle4 skies, with much better visibility in the southern direction than northern. Can easily see milky was with naked eye
• Budget? 1500€ absolute maximum, ideally less than 1000. (either used or new)
• Used? Yes, no issue. (I've been looking at EOS r5, some Mark ii cameras, Sony A7 III, Nikon Z series)
• DSLR or mirrorless - zero idea.
• I do have an EQ mounted shitty Bresser skylux 70/700, I'm not even sure how, but maybe I could use that as a lens? I get very pretty image of the moon through it, would be great to actually take some pics of it.
• Tracker? A very big maybe in the future. Who knows if I'll actually like real astrophoto.