The Beaulieu R16 takes a 100ft magazine inside, or can be used with an external 200ft 'mouse ears' magazine which sits on top of the camera. The cameras support speeds from a single frame up to 64fps, and some models have an auto-focus function (which only works with the correct lens). Most R16s also have a built-in light meter, although it's very basic.
The Beaulieu R16 can be used to shoot sync sound (it has a sync mechanical sync output), however they tend to be a bit noisy in a confined space. The magazines are notoriously fiddly to load, so you need to make sure you do all your loading in a comfortable place with plenty of time.
What's it worth? Take a look at this list of: sold Beaulieu R16 for a value indication.