The only way to tackle this problem (with all tout sales not just for this event) is for people to be permitted to bid the price through the roof.

The sellers will be charged by eBay for the final listing fee so eBay get a massive cut which keeps them happy and you stop other people getting ripped off. You should be able to argue that you aren't paying for the item because it is not allowed to be resold - I'd like to see the sellers try to kick up a stink over non-payment for an item they are not allowed to be selling in the first place.