Where can I safely sell a Casascius version 1 physical bitcoin (with hologram error) for cash? I have one of the Casascius coins (this one, to be exact) that contains an error: the small lettering on the hologram reads "Casacius", without the second 's'. I'm a inexperienced when it comes to all things bitcoin, as well as all things collectable. 

I understand that one can sell these coins for a premium over their BTC value. Where can I put the coin up for sale relatively safely? I'm willing to sacrifice getting the highest possible price in order not to get scammed.
There is a fairly robust market for these on ebay.  One sells every few days.  I have bought several from ebay with no problems (except for my underperforming post office).

PayPal is a little frustrating but you get used to it.

Be sure to post a good quality photo of the hologram and clearly describe the that it is a V1 error coin.