The one thing is getting lost here is the PURPOSE and USE of the bike. I was in the same boat as the OP. I wanted to get back into Mountain Biking and I set a $500 budget for a decent used bike to get back into it. Then after I got my feet wet and figured out if I wanted to get deeper, then I could mod the bike and do some upgrades. I looked for a while and realized that I didn't really want a used bike and that time was money and I can afford to up the price a bit. I decided I wanted 3 things in a bike. 1x drivetrain, hydro disco brakes and a decent fork. Well new there was only 1 but under $1k that I looked at that had 1x drivetrain. I rode it. A few times. Rode other bikes that were priced the same and some that were cheaper. I settled on getting a $700 (on sale) bike vs a $500 because it had 2 out of three of the things I wanted. So I ended up with a 2020 Specialized Rockhopper Comp 1x. Is it perfect? Nope...but its the perfect bike for me right now. Its light enough not to be a tank. Its agile enough to feel confident maneuvering. Stops great, and has a great range of gears. Its got a coil fork and while I wish I had an air fork, but this one has been great so far and right now I am not sure I would notice the difference. Its got QR hubs, and sure I wish it had Thru-Axle, but that's only because people say its better...right now I wouldn't know the difference. I wish it had a tapered head tube, but again...right now I wouldn't know the difference so it doesn't affect my riding. So its easy to say hey get a $1500 bike with a light frame, air shock, carbon bits, high performance brakes and drivetrain, tubeless tires and light wheels. The question is will the OP NEED all that bike for pulling around a trailer and some light trail duty? NO...
So my advice to OP, because I went through this for a few months until I bought a bike 3 weeks ago, is RIDE the bikes you are looking at. Go to various bike shops and ride models between $300-$800. This lets you know what you like. See what fits YOU best. How it feels to YOU. Then buy the one that works best for you. You may decide the difference between a $400 bike and the $600 bike isn't that big of a deal. Its a personal decision and you shouldn't buy a bike from the internet..fit, comfort, and how it feels are ALL huge factors that you will only get first hand test riding bikes. I knew really fast test riding certain bikes that I DIDNT like the way they felt. Good thing because some of this bikes were suggested to me.
Since I have had the bike I have been riding a bunch and learning TONS about riding again. The forums have made me wish I had spent another $300 and gotten the Rockhopper Expert 1x with an air shock, different wheels, tapered head tube, lighter frame, etc...then I realized...none of that would make the grin I get any bigger when I am riding nor will I be able to take advantage of those options because I am on beginner trails and at 50 do NOT have the desire to get too hardcore. If I do reach the limitations of this bike (which I seriously doubt I will) I can sell this for $400-500 and then use that to upgrade to a new bike that has more. Add another $500 which is the price of a good shock and I have an upgraded bike. Maybe even less if I get a new last years model.
My .02. Now go test ride some bikes, then get one so you can start to get some saddle time!