Price to identify maps

Today, we (players in w5) just noticed a difference in prices to identify maps. It appears that this is dependent on a player's Nobility rank.

Nobility : Sir or lower
Ordinary Map (Black) : 200 gold
Excellent Map (Green) : 500 gold
Superior Map (Blue) : 1000 gold
Legend Map (Purple) : 100 diamonds (or tickets)

Nobility : Knight or higher
Ordinary Map (Black) : 100 gold
Excellent Map (Green) : 200 gold
Superior Map (Blue) : 500 gold
Legend Map (Purple) : 50 diamonds (or tickets)

Nobility : Marquis or higher
Ordinary Map (Black) : 50 gold
Excellent Map (Green) : 100 gold
Superior Map (Blue) : 200 gold
Legend Map (Purple) : 25 diamonds (or tickets)

Nobility : Prince
Ordinary Map (Black) : FREE
Excellent Map (Green) : 50 gold
Superior Map (Blue) : 100 gold
Legend Map (Purple) : 5 diamonds (or tickets)

Knight is still probably the most achievable rank, and good enough to identify blue maps at a discount. At prince, it might be worth the 5 tickets to identify the purple maps.

Credits :
Nuloej was the first to suggest that it may be rank related, and impimp proved that it was Nobility when he upgraded from Sir to Knight.
pectrox provided the update for Duke and Prince. (updated Feb-1, 2011).