I have a Celestron f/6.3 focal reducer/field corrector for sale. This is the version that screws into the visual back of a Schmidt Cassegrain Telescope.
Includes original box, and both plastic endcaps. I just purchased a Lumicon Giant Easyguider, so I no longer need this. It's on Orion's web site right now for $159. You can have it from me for $100, including priority shipping.
I prefer PayPal, but I will accept money order or check. Money order or PayPal gets it shipped the next business day, or give 7 days for check to clear.