Ge have updated price of all items so just go to ge and click "Buy" and type in "runes" or you can go to wiki and find the price of it.
In the Grand Exchange, you can buy Mind Runes for 8gp right now. It may be a little more expensive to buy them in a shop.
Air runes cost about 12 GP on the Grand Exchange. They are probably worth about 20 on the street.
45gp from a fishing shop, 145gp from the grand exchange
i costs about 20mil-120mil
The Cost of any item is dependant on the popularity at the "Grand Exchange" You can check all current prices by going to the Runescape homepage, scrolling over to the 'Community" tab, and select Grand Exchange. Then, type in the item you'd like to have the price checked on.
The magic tree seed costs around 300,000 coins. Search the item on the Grand Exchange to get the current price.
52181 x 310 ( Current Mid Price ) = 16,176,110 Gp
Bump
The price of Yews and all items are determined by the Grand Exchange, which means prices change often. The current price of 1 Yew is 487 - 500 Yews at that price is 243,500gp. If you want to check the prices you can go in game to the Grand Exchange or you can use the link below. It takes you straight to the Grand Exchange link on the RuneScape website.
Since the price of items varies over time (it depends on supply and demand), better look up the current price in the Grand Exchange - either within the game, or from the main menu, witth the option "Game Guide - Grand Exchange".
To find out how much they cost at any given time would be near impossible, so check the grand exchange either in-game or on the main runescape page.
check the grand exchange.