That does make it difficult, but I'm sure it could be worked around.
One method could be that everyone could 'shotgun' one army, then organise trades separate to the purchase (eg. I could 'shotgun' all Brettonian models, then organise to trade the peasants with ruiza97). People could also have preferences- eg. Pref 1: Dark Elves, Pref 2: Brettonians, Pref 3: VC, and the preference you get depends on how much you're willing to contribute (see below).
Any unclaimed blisters could be sorted by a random choice process. Eg. Divide all remaining blisters into groups (randomly), assign these groups to different people (randomly), then have a 'choose one from the group, pass the group to the left' system. Obviously this would be done online, not by actually sending the models around.
Once it's all sorted people could trade, keep or sell from their stash as they want.
We could even divide the entire lot like that and then just let trades sort things out in a fair manner.
I guess the most important point it comes down to is: How much are people willing to put in? I'd seriously consider $400+ US, as I think that selling and trading anything I receive but don't want is probably worth it.