Looking for a physical braille input device to use with an iPad

Braille on Apple Products

Hi all,

I'm looking for a device with a physical braille keyboard which works with iOS for a student who is learning braille. They don't have a lot of money to spend, so I'm either looking for a standalone braille keyboard (if such a thing exists) or the cheapest possible braille display which supports input. The user is a Spanish speaker and will need a device which supports the Spanish braille code, and they'll be using it in conjunction with VoiceOver running on an iPad.

Many thanks.