Counter-Strike: Source, Day of Defeat: Source, and Half-Life 2: Deathmatch is $30
Half-Life 2 is $20
Half-Life: Source, Half-Life Deathmatch: Source is $10
CS 1.6 is $10
Team Fortress Classic, Opposing Force, Half-Life, Half-Life: Blue Shift is $15
So in total the account is worth about...