[Crazymax]

Try this...

pawn Code:

public OnPlayerRequestSpawn(playerid)
{
    if(GetPlayerSkin(playerid) == 1)//the skinid of your special class)
    {
           if(GetPlayerScore(playerid) < 100) {
                 SendClientMessage(playerid, -1, "Error: You don't have 100 score!");
                 return 0;
           }
    }
    return 1;
}