As mentioned previously, you would have your main (or at least main account) inviting the trials into the party and taking the money.
The idea here isn't to have 1 wand on 1 trial, but to have a raid of multiple trial accounts composing of all the wands allowing you to sell the full achievement.
Although I did it with live accounts and not trial, I'm merely responding to the questions posed.
I have been able to sell the full achievement at 250 gold a time, it takes a bit of remembering which characters on which accounts have each wand but it works. I have made thousands since the event started, no signs of it slowing yet either.