Hey,
I used to play on a Casio Privia PX-150 and it lasted me a good 3 years and I think it’s great for beginners and intermediate players. The better and newer models that are kind of the “upgrade” from the PX-150 are also great and most of them should fit your budget. I’m pretty sure they don’t even sell the PX-150s anymore. I probably would recommend the Casio Privia PX-770 or the PX-870, the PX-870 being an upgrade from the PX-770, which is an upgrade from the PX-150. They are both good and I would recommend them, and it looks like the PX-770 is $750 USD and the PX-870 is $999 USD on Amazon.
Obviously, an acoustic is far better in so many ways, but, if that’s not really an option, the ones I recommended to you would be good, but, to be honest, most digitals would be okay as long as they have grand piano action in them(most do). A beginner shouldn't need an acoustic piano immediately, but I would definitely look into investing into one at some point, they are far better than digital pianos.
Hope this helps,
Alex