I would be interested in buying 1 CALL contract (covering 100 BTC) at DEC 31 2014 expiry with strike price $500.
Accepting offers.
A CALL for that amount expiring today would have approximately 100 * (650-500) = $15,000 in intrinsic value. Add 205 days of time value premium, where historically the underlier has ranged from $400 to $1000 over a similar period of time, a standard deviation of ~50% of log returns.
And we can estimate that today this Call option is worth a total of approximately $60,000, but any writer in their correct mind, would need to add on a charge of 5 to 10%, in order to expect a profit.
You need to have a liquid options market for options trading to really be effective. With enough buyers/sellers in a market then individual participants will have their own motives (speculation, hedging) that can help set prices.