Shopping early with the attrition rate of Cups fields is not to be advised at this late stage... More than anything, the top horses in the market are having a day off on Saturday, so we are not likely to see too much movement at the top of the market.
The ones that could come in are going to be based on their performances in the Mackinnon and the Saab. Lets first consider the Saab.
Motley, motley bunch of runners in the Saab this year. The market will be very uninterested in the winner of this (as will I) unless it is Moatize. Moatize - always had potential and will be smashed in betting due to that and the Cummings factor if it wins the Saab handily - which looks possible. $3 each way for now at $100+ sounds like a plan.
The Mackinnon is more interesting for early betting at this point. Three horses could re-enter the collective consciousness with good runs in this race: Red Ruler, Barbaricus and Littorio. If you are interested in these ones, get in before the weekend.
Otherwise, you are probably going to do yourself a lot of favours by keeping it in the pants until Tuesday morning. Apart from the four I have mentioned, I can't see anything that will start tighter than what they are paying now.