Would you offer a better price on a smaller deal? Say $35 for 500?
You might wish to place a call option bid on Bitcoin-OTC:
Call Options using ClearCoin Escrow http://wiki.bitcoin-otc.com/wiki/Option_orders
The syntax for your inquiry above would be entered as:
;;buy 500 btc at 1.00 PPUSD "call option premium 0.07 PPUSD expires 01Apr11"
The premium for $0.07 PPUSD for each of the 500 BTC optioned totals $35.
So that would be a good deal for anyone who thinks Bitcoins will still be worth less than $1.07 at the end of March and wishes to earn $35 for simply putting 500 BTC in escrow for about 40 days. [Edit: the option seller earns $35 less the 4 BTC escrow fee for 500 bitcoin escrow].