Thousands of frames per second?
The Casio EX-F1 can shoot upto 1200fps, but the resolution reduces as the frame rate gets higher.  They go on eBay for about £600.

http://www.casio.com/products/archive/Digital_Cameras/High-Speed/EX-F1/

Or the Casio Exilim FH20, for about £300 on Amazon, was used to make this:


                
            

More info on how it was made here:

http://straylight.co.uk/?p=120