Gold Coin investment

I wonder how much would it cost me to buy a gold coin from the www.usgoldbureau.com - the famous and leading seller of precious golds and silvers - in every form. Though I think my saved up money is still not enough to buy even a small piece, knowing the price will at least make me plan on saving up more in order to purchase this super cool investment piece.. that for sure will double it's price in the years to come! Now I get it why those hardcore investors truly make it to point that they buy coins as much as they can because they know that their investment money will earn big! Well you know, we gotta learn from them so we can be like them too! :D