>I'm designing a cheap consumer product and need to find a 500K HZ (.5 MHZ)
>timing source accurate to within 2-5%.
>
>Can anyone recommend a cheap crystal or ceramic resinator?
>
>I'd like to keep the cost under $.50 ea / 1000.

If you can go down to 455 kHz, there are cheap ceramic resonators usually
used for superhet AM radios (what's a ZF in English ?).
Otherwise - no Idea. Crystals in that range tend to be somewhat expensive,
you might perhaps use a higher freq. crystal (e.g. 4 MHz, they drop in
price at around there according to my catalogue) and a couple of flipflops
(three in that case).

Bye
  Markus