Want to start learning keyboard - How much do I need, to start?

I want to get into writing my own music, and my Mom's offered to teach me piano, which I figure I can apply to keyboard, and then plug into a site like Bandlab, which appears to come with all sorts of instrument plug-ins.
My question is, should I spare some money for a sophisticated keyboard with lots of levers and functions, or does a site like Bandlab provide essentially all the tools I need, and a cheap keyboard would serve fine?
Would getting an expensive keyboard be like forking out for an expensive camera, just to find the camera on a phone can cover your bases, these days?