Mike Van Der Linden

Hi Guys, Mike from the Netherlands here. I had a really silly question. Me and a mate are heading over to Liverpool in the weekend of the 24th of april and really wanted to visit the Everton- Manu game. But the site says i need a "prior purchase history"...since we are from the other side of the ditch we dont have that. Does anyone know a cheap ticket seller where we can buy tickets before the actual match day? Many thanks for the reply!!