Nos operamur, te ludere
"Life is more fun if you play games." - Roald Dahl
It's a little confusing. So if I played a vault that had priority 6 and the other tied person played one with priority 4, do I win?
I think you do win, but I agree that the rulebook is cryptic about this.
On page 7 it says "In increasing order of Vault Priority, each player
will become the Auction Master while all other players are Bidders in that Auction." That means the lowest numbered vault is auctioned first.
For the tiebreaker on page 13, it says "Ties are broken by the player with the least number of Corruption Tokens, then by descending final Vault Priority."
It seems to me that "increasing" and "descending" are opposites, so it would be the person who played the vault with the highest priority number. This might also make sense since a high number at the end is harder to win with?