Thanks for your input, scubaman.
I had generally the same thoughts (if it has an aluminum frame and Shimano components, it can't be too terrible. I think...)
I do have a lot of hesitation about buying a no-name (or something like Mongoose) bike from Amazon, but then, I know people who have done it and are happy with the bikes. I'd love to buy a better used bike locally but not sure it's possible (I guess fatbikes aren't popular enough to make it into the used bike market ... never see them used.)
I moved recently and have not been to any of the bike shops in this area, so I plan to contact a few of them and see if anyone carries fatbikes and what they might have to say about them (with specialty bikes, though, I think most shops feel it's only worth their while to carry the highest of the high end, so I don't expect that they'd have anything in the budget price range, even without covid-related shortages taken into account. But still worth talking to them.) I do have 2 other bikes already so I want to form a relationship with the local shops anyway.