There isn’t a shortage of good pages to find out about this machine.  Here is a page detailing restoration.

Here is a recent bloggingheads episode featuring a Wimshurst and a good explanation of how it works.

It’s a pretty low rent venture here, so you’ll have to click here for a simple diagram and here for photos. Apologies.

Does anyone know where I can get one at a good price?

See also:  Electrostatic induction, Leyden Jars, Van De Graaff, Tesla Coil, Singing Tesla Coil

Addition:  Here’s a good page for direct current electrostatic devices.

Addition:  New bloggingheads this week has a Ruhmkorff coil and a De La Rive tube demonstration.  Er…yes, Ruhmkorff and De La Rive.

Best explanation I’ve of how a Wimshurst works here.