It's all difficult to compare, since so much depends on where you live, and how you want to live.
We used to own several condo's in Noble Remix in Bangkok. 50m2 and we used to get ฿30,000/month for them, shoebox's really but nice and in a great location.
We now own condo's back in the US, 1000ft2, or 92m2 and we rent them for $1000/month, so the same, still rather nice in a great part of town.
Food is always tricky and it depends how 'local' you want to go.
I was never into buying meat at one of those outdoor stalls with the swirling fan trying to keep the flies away, I'd always pay more in Top's for meat that at least looked more hygienic.
For sure our grocery bill is higher in the US than when we are in Thailand, but last time the gap is narrowing, but again, ain't prepared to go full native
Utilities not much in it, and at least the power stays on all time time here!
You said you are on Medicare, so you're at least paying Part B. If you get an Advantage plan they do cover you for overseas travel, which might be worth looking into, then you're not committing yourself to be reliant on the local Government hospitals, which outside BKK vary wildly to say the least