Spend my $100 for me please

I am in the process of ordering some books from amazon and am willing to spend up to $100 on stock (not including shipping and handling and ordering fees) so far my list includes;

Middle limit Hold'em by Bob
Weighing the odds by King
Hold'em for advanced players by 2+2
The theory of poker by 2+2
Total = around the $70 mark

are there any other essentials that I'm missing here. I suppose I'll give you a little background here. I'm a low limit semi-pro who is under booked. My library consists solely of Ken warren books and a Jhon Vorhaus (Killer Poker). I play limit exclusively and need a better knoledge base. I have set aside this period in my development to max out my learning curve and that means reading and studing and posting and studying on a one-one basis with playing and quite frankly my libary is just too small and weak to hold my attention