Hey strangers, long time, no see. Good to see a few names still the same... About a year ago my DSLR died and other things have been higher priority than replacing it. The problem is, technology has moved on and it hasn't moved in a direction I like. I have been using superzoom lenses since the film days (Tamron 28-300 followed by a Sony 18-250). I started in the Minolta ecosystem and have evolved to Sony, my last body being an Alpha 55. The problem is, that generation was the last to use the A mount. The mirrorless systems that have followed do not offer a Superzoom option. So, the question is, where do I go from here? The obvious choice is a Sony Alpha 77 from the same generation as my old body which will continue to use my 18-250 lens, and gives me more resolution, better video etc. I would still be buying a used body that is at least 10 years old. Alternatively, I could switch to a different brand that has a newer body still compatible with superzoom lenses, but that would require buying both body and lens. Anymore, I mostly shoot video for my YouTube channel, but I also miss the ability to shoot stills occasionally. Switching back and forth between lenses is not something I want to do again. Absolute top end budget would be $1500, would prefer to spend maybe a third of that.
When I was involved in photography, Nikon was the only camera manufacturer that hadn't changed their lens mounts. That may have changed now, though, but it was certainly true a few years ago.
Nikon DSLRs are still using the Nikon F mount albeit with electronic connections etc. The new Nikon mirrorless Z system uses a new larger mount which takes Nikon F mount lenses with an adaptor, so they have some backwards compatibility. As to changing from Sony DSLR, you could adapt your 18-250 to a used Sony A7x full frame mirrorless camera. You could probably switch to any of the other systems and have a similar quality used setup for similar money. Canon, Nikon and Sony are the big 3 with Pentax still hanging in there. Find a camera that works for you in terms of spec and handling and take it from there. Loads of DSLRs to choose from plus mirrorless from the big 3 and Fujifilm
I'm not sure if this would be the one or feasible, but perhaps an adapter like this one might do the job, if you were considering a more recent Sony body to re-use your lenses. The a99v is about half your max budget. a77ii is a little less. a77 can be bagged for a bargain for what it is.