I always liked bands with keyboards, too. Nowadays just about everyone has synths, but when I was young there were a lot of bands that had just drums, bass, guitars, and vocals. Sometimes I would buy an album from a band I'd never heard, simply because the back of the cover listed a keyboardist!
If you have a lot of money, you'll probably want to buy a good arranger or workstation keyboard-- although it might be a better idea to start with an inexpensive MIDI keyboard controller and a free or inexpensive DAW with a good assortment of VST instruments, so you can get your feet wet without investing too much money. It's a lot different today than when I was young, because there are some very good free soft synths, so you don't need to spend several thousands of dollars just to experiment with a synth to see if it's for you. And if you're more interested in playing a piano, electric piano, or organ than a synth, there are programs (or "patches") for pianos, organs, guitars, basses, violins, flutes, choirs, etc.
Then if, after testing the waters with a MIDI keyboard controller and VST instruments, you decide you definitely want to pursue keyboards more seriously, you can buy a really nice arranger or workstation keyboard.