PE prices are very unlikely to go up, and are readily available JFK-SYD, so you might as well wait for a sale. Though odds are quite low that the price will drop any from JFK. You might try DFW-SYD for pricing, that tends to be considerably cheaper than JFK-LAX-SYD at times. In fact there is a PE sale on now for DFW-SYD (not sure what date it ends, might be very soon).