I'll sum it up - it is not how much you earn, it is how much you keep.
In other words, don't buy the books - save the money.

__________________
Thank You!
Fred
2009 ML350
2004 SL600
2004 SL500
1996 SL600
2002 SLK32
2005 CLK320 cabrio
2003 ML350
1997 C280 Sport