Only the devs know how long they will allow the mithril to be purchasable, and that info has not been disclosed as of yet to the KaWmunnity. As far as the complaints about the mithril price or that it's just a ploy to get people to buy crystals and nobility; keep on mind that you don't have to get the mithril, just do without.
For me each mithril costs 309,000,000. Everyday I can only buy 29. That means I spend 8,961,000,000 a day on just mithril.
The last time they sold mith it was for 1 week. If this is the same as last time there is 3 days left including today to buy mith.
In a mithril war it takes 24 hours of hitting to get 6-10 mithril. On average u can make 15-20 billion a day doing hauntings. Buying 51 mithril at 400 mill costs me 20.4 bill. Do the math, I need to do 5 days of mithril wars which costs me conservatively 75 bill. So I save 55 bill buy buying mithril. What a bargain!
I can purchase 50 a day some can buy 51 some can only buy less. It's based off of total strength and lands owned is my best guess.
HLBC Hansel can buy 49, HLBC Fighter builds 50 or 51, HLLC Hansel (with guilds instead of SoS) 40,... Cost is 300 mil for small accounts, up to 400 mil for big accounts. Those who want to reset should buy 12 mithril and explore 4 highlands, resetting with all 4 stat boost spells active is fun.