Why don't you take out a subscription to Safari Books Online (http://safari.oreilly.com)?
For Unlimited Access (read any book you like online, plus download 5 PDF chapters every month) it costs $43 per month; that's far less than you're spending now on a just a few "hard" copies.
At the moment there are over 5500 books to choose from (plus training videos). If you're solely looking at books from Microsoft Press there are over 300. Here are some of the latest Microsoft Press books available:
- Windows SharePoint Services 3.0 Inside Out
- IIS 7.0 Administrator's Pocket Consultant
- Inside MS Exchange Server 2007 Web Services
- MS Expression Web Step by Step
- Windows Vista: Home Networking
- Beyond Bullet Points
- Windows Vista: Home Entertainment
- Inside MS SQL Server 2005
- MCITP Self-Paced Training Kit (Exam 70-623)
- MCITP Self-Paced Training Kit (Exam 70-441)
- Practical Project Initiation
- 3D Programming for Windows
- Progamming MS Composite UI Application Block and Smart Client Software Factory
- MCITP Self-Paced Training Kit (Exam 70-622)
- MS Office Publisher 2007 Step by Step
I've been a subscriber for a couple of years, and it's saved me $100s in buying books.
Hope that helps,
Phil