The only way that could work is if someone is willing, and has the time, to take in all the prizes on offer and then sell them.
Personally, I have neither the time nor the patience for selling stuff direct. Either using eBay which would generate the most cash, or in the for sale section on here. If you remember last time, the biggest hassle for everyone was getting stuff wrapped and posted. If it came down to selling things to generate cash I'd just chip in another donation and not do anything with the bits I put up.
It'd also turn the forum involvement into a straight forward money hand over, which would remove a lot of the chat and entertainment.
I have no problem with whichever way you want to do things, both ways generate money for the cause. Just let us know what you want to do and go from there.