I maintain the AT101W should be everyone's first mechanical keyboard.
They're super common, I picked up another one myself today, in fact. You shouldn't pay more than £20 at most, and that's for a really good one. I don't even bother to sell mine because they wouldn't raise enough money to be worth the time
. But if you look around you can often get them for free in all kinds of buildings as stowaways.
Its switches aren't great if you've tried many other switches before, but they're not bad either, and they give a great introduction to mechs as they're excellent all-rounders. From there on, you should be able to much more easily decide what future boards you might be into.
They're also very well-built, much better than many modern mechanical keyboards, and they look charismatic and imposing IMO
.