The Mark 02 is the only wildcard because its an exclusive to one site which means that'll be a selling mark for a while.
Here is my take on it. The MR/WS Iron Man Comic Mark I helmets retailed for $349.99 (Silver) and $399.99 (Gold) respectively. I bought my Gold for $160 from a retailer site (Statue Toys) and just got my Silver last week for $150 shipped. That is a drastic drop of a little over 60% and those are excellently done. If the Mark 03 which is retailing at $424.99 takes the same drop you're looking at about $280 helmets and lower.
My advice is if you know you won't like it, get it and flip to try and recoup your funds while the Iron Man kick is still there. If you wait too long though especially in this economy you'll probably lose a lot more than $130 trying to unload it. Like I said, I would buy them around $250 and history has shown that I will own them at that price if I just wait a few months.