I've added a new link in the sidebar for Mahasamatman's Guardians Trade Page. If you need cards and are looking to trade, buy, or sell, it's a great source for doing so.
I was recently able to obtain Oscar the Wonder Chimp, Shin Chios, Professor Heisenburg, Standard of the Elements, and Vek-Nadra from the contacts I made on that site. That leaves me 3 cards from completing my collection - I still need Black Locust, Gateway to Mystfall, and Little Voodoo Hat. The site has been a godsend in allowing me to obtain cards that seem to be impossible to find elsewhere.
I would like to take a moment to recommend a Hungarian gentleman by the name of Istvan Suranyi, he is a great person to trade with and shipping to and from Hungary is faster than you might think. Also, there is a French individual named Pilato Sébastien who is not on the site but watches for trades. This person is also a reputable trader, from my dealings with them.