Ok, with the help of a fellow Siegeian I was able to find out proper prices. I estimate the value of the 120 Mystic about 2.5-3 mil and the 120 tactics about 5 mil.
I can offer the scrolls for these prices:
120 Mystic: 2 m
120 Tactics: 4 m
As always, I will also accept fair offers depending on my sympathy for the person ;-)