I've not bought centerfire ammo for years. 45 ACP, 454 Casull, 44 Mag, .223/5.56, and .308/7.62. I reload them all. The only ammo I've bought has been .17hmr and .22. Reloads shoot as well and often times better than factory ammo. My biggest problems have been powder and primer shortages at times. . . Your cost ends up being 50% or less than store bought , and, It's a pretty good hobby .
Save your money and get a D500 . . . It is likely the best DX Nikon camera and can use all of your current lenses. I upgraded from a D5500 a couple years ago and kept the D5500 as a backup . . . I never used it because the D500 is so awesome. So hang onto what you have until you save a little more up to get the D500. You won't regret it. The D500 is simply the best there is . . .
I'd recommend a new or used Nikon D750. It should be close in controls/operation/features of your D610. The D750 is somewhat of an upgrade . . .
I attend a lot of school and other activities of the grandkids . . . Mostly indoors. The monopod adds weight, but makes it so much easier for shots in lower light, and especially for video of all the band concerts, taekwondo tournaments, dance recitals, etc. Not really needed that much outdoors unless shooting video and tripod is not practical.
Best walk about lens for me is the Tamron 18-400. Covers just about all my needs. . . .
Steller's Jay . . . We have 4 or 5 that frequent my back deck because my wife gives them peanuts . . .
A lot of folks like the Tamron 150 - 600 mm lens. It's about $1400. On a cropped frame camera it's 900mm equivalent on the long end. I have one for my Nikon and really like it. For a walk about lens, I have the Tamron 18-400mm. They run about $700. On a cropped frame camera, it's about 600mm equivalent on the long end. IMHO, the cheap Vivitar you mentioned is probably junk. Of course, Canon probably has something similar to the Tamrons that I mentioned. . . .
I went from a D3300 to a D5500 and then to a D500. Many folks like the D7200/D7500 cameras . . . I skipped them and went to the D500. The D500 is the BEST DX camera existent. If you can afford a few more bucks, I suggest you get the D500 . . .
I thought about upgrading my D5500 to a 7200, but when in the store, I tried the D500 and fell in love with it. And it does have a dedicated focus button. I recommend the D500 . . .
The D500 is the "top of the line" cropped frame (DX) camera . . . Why not also own the "top of the line" (FX) camera . . . The D850 ?
My favorite backyard bird . . .
I like the top one . . . Very nice . . .
I put the Arca Swiss ball heads and gimble heads on all my tripods/monopods. It just makes things simpler . . . All my cameras/lense collars have Arca Swiss plates . . . Everything works with everything and I never have to change plates.