I bought a cheap used one off of eBay, it wasn't too expensive - a few hundred bucks. I know that nicer ones can get up there, though. Learning braille was an unusual challenge, but I didn't find it especially difficult. It only took a couple of days to become reasonably proficient with it. The braille display I ended up with is pretty nice despite its price tag, it has a good finger-feel to it and has a nice set of basic features.

The most difficult thing for me would be learning advanced levels of braille, which involves memorizing shortened forms of many words, but I reckon I can get away with just using long-form for a good long while.