On walmart.com, I found a couple that go up to 550-560 for less than 50 dollars.

I've had the same problem. I've been told using two analog scales, one for each foot, but that doesn't quite add up. For my last 40 (maybe 50 at this point 🥴? Haven't been in a while) I've been going to a clinic and asking to use theirs. They go up to 500 or 600 I believe. Other than that, I guess just getting a more expensive scale online. I'm unsure of accessibility or accuracy of something like an animal or freight scale.

A bigger belly makes you feel more powerful, but too big a belly makes you weak, muscles too busy carrying weight to do powerful things.

As long as I've been fat, my gut has never folded in or added rolls, just one ever-larger dome. My back was doing the same, fat swelling on my shoulders and under my arms to meet my moobs. Now it seems I'm growing a new roll beneath that, raising the first one and heading down my back. Has anyone else grown multiple back rolls?

I can't get in. I can't honestly remember if I even made an account.

Stamina definitely goes. At over 430 and not super active, running is very hard and walking nonstop is too much in about 20 minutes.

Another thing, eat late at night, then sleep. Goes straight to fat.
Also, drink calories. Milkshakes or juice, both high in cals and sugar.

For gaining:
1.BK
2.Hardees
3.Sonic
4.Taco Bell (not for straight calories per item, but for number of items I can consume)
5.Wendy's

All of these are high calorie per dollar, and all but Bell have ice cream to really fill in the gaps in your stomach.

Just keep eating. Work on expanding stomach capacity. That will make you feel hungrier more often. Perhaps try starting off a day with a peanut butter sandwich. Very calorie dense, but, at least to me, not too filling.
Junk food is another obvious choice, but not too much, just more than you have before.

Yeah, a horizontal stripe polo shirt that's too small is basically the choice for worst look for me.