You can set an integer variable to a specific player's current gold through "Player - Player property."
Trigger:
Set test = (Player 1 (Red) Current gold)
A more specific example for what you want would probably be these 2 example triggers.
Trigger:
Map Initialization
Events
Map initialization
Conditions
Actions
Set Players = (All players matching (((Matching player) slot status) Equal to Is playing))
Trigger:
Find current gold
Events
Conditions
Actions
Leaderboard - Create a leaderboard for Players titled Gold
Leaderboard - Hide (Last created leaderboard)
Player Group - Pick every player in Players and do (Actions)
Loop - Actions
Set test[(Player number of (Picked player))] = ((Picked player) Current gold)
Leaderboard - Add (Picked player) to (Last created leaderboard) with label (Name of (Picked player)) and value test[(Player number of (Picked player))]
Leaderboard - Sort (Last created leaderboard) by Value in Descending order
Game - Victory (Player in position 1 of (Last created leaderboard)) (Show dialogs, Show scores)
For each (Integer A) from 2 to (Number of players in Players), do (Actions)
Loop - Actions
Game - Defeat (Player in position (Integer A) of (Last created leaderboard)) with the message: Defeat!
The bracket index of the variable will reflect the gold for that player. for example, Player_gold[1] will be player 1's gold.
EDIT: I didn't originally see that you wanted to make victory/defeat conditions from it my bad. Try this approach! It adds each player into an invisible leader board with their current gold as their score, it then sorts them in descending order, and then makes the player in the first position the winner, and everyone else the loser.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.