Hi,
You can get it at Ruby Photo or Cathay Photo. I got mine at $280, but for it to be used with Oly, you'll need the adaptor SCA 3202 which costs $90. Thereafter, this flash can be used on the E10, E20 and C5050 (not sure about C750 but I think it'll work as well).
I think the prices should be around this region.
Cheers,
Mike