Access Control

I would like to start getting together some ideas for the access control system for the space. At the moment, it looks like we are going to have to roll our own solution, unless someone can point out a commercially available option that meets our requirements and is under $300. Features:

• RFID and PIN for dual factor authentication
• Web interface for adding and removing access rights
• Access logging
• Disposable PINs (can assign a PIN and card that will auto expire at a set date and time)
• Support 30+ users * Email alerts
• Remote management, either through mobile web interface or smartphone app
• Must be able to run off UPS or battery backup