A 50k gold is an item in Evony TKR (The King's Return).
The description of 50K Gold in Evony TKR says:
Use it to gain 50,000 Gold.
50K Gold is known to potentially be obtainable from opening Lucky Box Ⅱ, Lucky Box Ⅲ, Junior Warlord Chest, Pile of Gold and Bulk of Gold. The links for each item are below:
Note: This list may be incomplete.